Can a motorbike out brake a car?

[rocketman1]

Just riding behind a van on a tight back road coming down a hill, the van driver braked very heavily for a road off to the right, he couldnt turn right because of a car coming the other way that he had to give way to.
I only just managed to stop, ie the road was so narrow I could get by, I would have ended up in the ditch.
It got me thinking, my bike is new, older bikes probably dont have such good brakes, how would they got on in the same situation.
The question is can a motorbike out brake a new car with ABS etc
Ques. Do I have stay more than 10 car lengths behind a van/car at say 100kmh , can I safely stop in time?
It gave quite a fright actually, as I wasnt expecting such a quick stop,I was lucky to have my hand already with 2 fingers on the brake.
You live and learn another lesson aye

[skidMark]

Not a hope in hell.... less weight pinning it down and a bike has about 4 inches total tread on the gorund maximum at any time a car has 4x 8-10 inches.


The only reason a bike is quicker through a corner than your average car (not talking porsches etc), it because on the centrifugal forces.... leaning blah blah...

Anyways not too relevant buy short answer no.

[homer]

Think your asking it wrong
more to the point , you knew what may happend and you stoped .
The next car wouldnt have would they
cars do stop very quick
its the same principal
but how many have actually had to stop in a hurry

[Gubb]

2 second gap, 4 in the wet.

I'd imagine that A bike could out-brake a car, remember if your comparing cars with ABS, why not compare them with bikes that have ABS.

The stopping power of two wheels would have more effectiveness than 4 brakes on a car considering the extra weight they have to stop.

Always a good chance to go and practice emergency braking in an empty carpark though.

[Subike]

yes in my opinion
it also depends upon the ability of the rider
But I have stopped quicker than cars many times,
Not a problem
Its all a mater of practice, and how to apply your brakes to get the max out of them without lock up.
If bikes brakes were not better than cars, there would be a heap more white crosses on the sides of the roads than there is.
Practice you emergency braking often, keep it in tune with your riding.

[homer]

most people in a car couldnt stop in a 30 second gap
think about it

[skidMark]

2 second gap, 4 in the wet.

I'd imagine that A bike could out-brake a car, remember if your comparing cars with ABS, why not compare them with bikes that have ABS.

The stopping power of two wheels would have more effectiveness than 4 brakes on a car considering the extra weight they have to stop.

Always a good chance to go and practice emergency braking in an empty carpark though.


Extra weight but less pinning them down though.

a bike hard on the picks, like a car is going to dive down.

but sa car has alot more tread on it, yes the bike is less weight to stop...hmmmm be interesting to hear from somebody who knows all the physics involved etc.

[Macstar]

At the AWMR once I had about 6 runs at emergency braking at 100kph i.e. slam on the brakes and see how quick you can stop.

We didn't bust out a tape measure, but by the last couple of attempts I had managed to reduce my total stopping distance to between an estimated 12-15 metres at 100kph, in the dry with no ABS. I'd be surprised if your typical car could stop in that distance at 100kph...?

In the wet, I'd rate a car and would rather be in one too if i had to slam on the picks!

[skidMark]

yes in my opinion
it also depends upon the ability of the rider
But I have stopped quicker than cars many times,
Not a problem
Its all a mater of practice, and how to apply your brakes to get the max out of them without lock up.
If bikes brakes were not better than cars, there would be a heap more white crosses on the sides of the roads than there is.
Practice you emergency braking often, keep it in tune with your riding.


Well yeah i mean i can stop a bike from 60kph in 2 metres.

That is once reacted andd actually applying brakes.

But i have been in some cars that stop pretty bloodey fast.

As in hit the brakes and its stopped. 120 kph - 0 kph in err pass, a bloodey short distance thats for sure.

[homer]

thats why they make abs
its for people who dont know how to break
dont know how to feel what the cars doing

[scracha]

Lots of bike mags tested this. Generally a decent sprots bike slightly outbreaks the average family car in the dry on a decent road surface. A big factor is the stickier (but not so long wearing) rubber on bikes.

Try it in the wet or behind an expensive/modernish car and you're saying "hello" to the rear passengers.

MINIMUM 2 second gap in the dry. MINIMUM 4 seconds in the wet. Multiply that by 2 or 3 on gravel/snow/ice/mud. It's scary how many bike riders sit right up cars arses.

[scumdog]

I've seen a bike stop in just over two metres from 100kmh.









Of course the truck it went into the side of kind of influenced its stopping distance

[jrandom]

This question comes up reasonably often; Jim2 has mentioned some test results indicating that bikes can, in fact, out-brake cars in the wet and the dry.

I'm fairly sure that actually doing so takes balls and skill, though. It's easy to stomp on the brake pedal in a car, particularly one with ABS, but hauling a bike to a quick controlled stop is a maneuver requiring care and precision.

[Weaver]

2 second gap, 4 in the wet.



With my drums all round, I should probably double that.

I believe that a bike will easily out brake an average car.

[scumdog]

. It's scary how many bike riders sit right up cars arses.


True dat.

Amazing how many motorcyclists have NO imagination.

[Gubb]

It's a legal requirement (WOF standard) that your bike can stop within 2 bike lengths from 50kmh.

[skidMark]

I've seen a bike stop in just over two metres from 100kmh.









Of course the truck it went into the side of kind of influenced its stopping distance


Oooo that made me cringe.

[homer]

I've seen a bike stop in just over two metres from 100kmh.









Of course the truck it went into the side of kind of influenced its stopping distance

so true i stopped in about .5 meters at once

[rachprice]

http://www.youtube.com/watch?v=7Oz44oGaI4c
I thought bikes would outbrake cars but then I dont know much at all!
btw fifth gear? what a fuckin rip off of top gear.

[Jantar]

Under ideal conditions a bike can (not will) outbrake a car. What you have experienced is an illustration of reaction time. At the time that you started braking the van had already peeled off quite a bit of speed. The fact that you didn't hit the van showed that you outbraked it quite considerably.

However a car with modern ABS can (again, not will) outbrake a bike without ABS. It all comes down to reaction time and driver/rider ability.

[Motu]

More important is can you maneuver while under hard braking? Your options are very limited on a bike,you practically have to do all your hard braking in a straight line.A car has more options in that department,there is a lot that can be done to change direction....with ABS you can damn near steer a car while hard on the picks.

[krad_nz]

The main difference is that braking quickly in an ABS equipt car requires very little skill to pull off successfully. Stomp the brake pedal and the ABS does the rest.

A bike on the other hand has to brake + remain up-right and composed throughout the whole procedure. This requires more skill to pull off.

So, your average car driver is going to get it right more often than your average biker, just because its easier in a car.

Also, if you consider that the majority(?) of bikes don't have ABS... well that skews things even more so in the favour of cars..... on average.

At the extremes in both cases I would still put money on the car. Ie: a top spec race bike vs a top spec race car and equal drivers/riders in both, car for the win.

Its just about converting kinetic energy (ie: moving object) into heat + noise without skidding.

Ceramic brakes these days mean that the difference in weight between a bike and car is no longer a limiting factor. Also, a car has twice as many brakes, and doesn't have to remain balanced etc.

All imho of course :)

The argument also depends on whether its straight line braking or braking while corning or avoiding an obstacle, cage, horse etc. :)

[Jantar]

It's a legal requirement (WOF standard) that your bike can stop within 2 bike lengths from 50kmh.

Pardon? Is it really a legal requirement that a bike can stop in 4.6 meters from 50 kmh? Since when is it a requirement that a bike must break all the known laws of physics?

[Subike]

there have even been occasions where cars have gone backwards under braking
but the truck was still going forward

but yes, SD I agree
too many riders dont give themselves the saftey net of distance, not only from the car in front but the one behind as well.
And sadly too often the one comming in the opposite direction.

[slopster]

It's a legal requirement (WOF standard) that your bike can stop within 2 bike lengths from 50kmh.

What the fuck that is impossible. I think you will find its more like 8m at 30kmh.

[slopster]

And ABS braking doesn't stop you quicker it just helps keep you in control if you panic and lock up the wheels. Or all the race cars would have it wouldn't they

[Mikkel]

A bike should be able to out-brake any car that doesn't make use of down force generating spoilers.

That said, it comes down to the skill of the rider - and if you stuff it up you'll be worse off on the bike of course.

A car, without ABS, is no more capable of braking hard and maneuvering than a bike is.

A car, without ABS, is no more capable of stopping quickly on wet/icy/loose surfaces than a bike is. But it is more stable, less prone to locking up on all wheels and less likely to fall over.

To some degree this of course requires a superb rider who can evaluate the surface, slope, weight distribution, tyre temperature and pressure and apply the optimal braking force to both wheels. Unlike a car a motorcycle can change the balance between front and rear brakes on the fly.

Add modern ABS and ESP systems in cars and you pretty much have to be omniscient to outperform the 4-wheeler...

[AllanB]

In that Mission Impossible movie on the Speed Triple (yummy) Tom (weirdo) Cruise stopped from god knows how fast on the front wheel while pulling a gun out of his pocket and then spun it around (while still doing before mentioned stoppie) and shot the baddie.

Hollywood is so full of crap - every motorcyclists knows to keep both hands on the bars when doing stoppies at 160.

[skidMark]

What the fuck that is impossible. I think you will find its more like 8m at 30kmh.


Well it's not hard really i made morcs rvf400 with "wooden brakes" stop in a bike length from 60kph in a carpark after being on it 30 seconds.

Can do that same on a zxr....

Takes a fair amount to lock a front wheel, ive had front wheels start locking and skidding and try tuck under etc.... the trick it to keep strong arms to keep the bars straight....once its crooked and it tucks, you are screwed.

In saying this though i do alot of stoppies, so i have practised braking alot.

[jrandom]

I had managed to reduce my total stopping distance to between an estimated 12-15 metres at 100kph...

That's impressive.

I've never measured my stopping distances.

I recall Autocar magazine testing a few supercars for best 0-100 and 100-0 times (an R34 GTR won overall) and the stopping distances from 100kph were in the order of 30 metres.

[Jantar]

Well it's not hard really i made morcs rvf400 with "wooden brakes" stop in a bike length from 60kph in a carpark after being on it 30 seconds.....
1 bike length = 2.3 m
60 kmh = 16.7 m/s
V^2 = 2*f*s
so f = 279/4.6
or f = 60 m/s/s ie 6 g.

That is 6 times what is physically possible, so stop talking crap SM.

[FJRider]

The key to good braking is reaction time(time taken to react), AFTER brain gets the message you do need to brake, and actually braking. At 100 km/hour about 28 meters is covered a second. Thats about 2.8 meters every 10ths of a second. So at a following distance of say 10 meters, and the vehicle in front STOPS(ie. hits something), you have about 2 and 1/2 tenths of a second before YOU are there. How goods YOUR reaction time ??? Are YOUR brakes up to it ???

[Jantar]

That's impressive.

I've never measured my stopping distances.

I recall Autocar magazine testing a few supercars for best 0-100 and 100-0 times (an R34 GTR won overall) and the stopping distances from 100kph were in the order of 30 metres.

The very stickiest bike tyres have been tested at just under 1G braking performance. That is equal to 38 m from 100 kmh.
So the data you give for supercars is in the right order. I have yet to see a bike decellerate at more than 1G unless there is some other outside inluence. Last year I stopped at 2.5G and I'm still waiting for the surgery as a result.

[FJRider]

It does help if YOU stop at the same speed as the BIKE.

[Jantar]

It does help if YOU stop at the same speed as the BIKE.
Geez, I hope not. The bike stopped at close to 5G. The previous rider who did that stopping performance on the same day was carted off by the flying doctor.
:doctor:

[FJRider]

But you weren't braking were you ???

[The Stranger]

Even IF a bike can out brake a car, can you?
It really is a skill that requires a bit of practice to get right and particularly to make it a natural reaction in an emergency situation.

One tip, which will no doubt be contested, don't cover your brake with 2 fingers. All or nothing.

Why everyone is rattling on about ABS I am not sure. ABS on most cars and all motorcycles (with the exception of some BMWs) increases stopping distances. Sure it allows for control, which is nice if there is an out, but if the extra few metres you loose with ABS means life and death, it sucks big time.

[Katman]

What the fuck that is impossible. I think you will find its more like 8m at 30kmh.

Close. It's actually 7 metres from 30kph.

[MaxB]

Even IF a bike can out brake a car, can you?
It really is a skill that requires a bit of practice to get right and particularly to make it a natural reaction in an emergency situation.

One tip, which will no doubt be contested, don't cover your brake with 2 fingers. All or nothing.

Why everyone is rattling on about ABS I am not sure. ABS on most cars and all motorcycles (with the exception of some BMWs) increases stopping distances. Sure it allows for control, which is nice if there is an out, but if the extra few metres you loose with ABS means life and death, it sucks big time.

Quite right. ABS is designed to retain steering control of the vehicle and as a trade off stopping distance is slightly increased. That is the whole point. That you retain car control. It allows the driver to stand on the brake pedal without risk of locking up. A lot of drivers don not realise this and follow too close thinking they are safe.

ABS does not work so well for bikes because of the changing contact patch on cornering. Some systems get round this by detecting the lean angle and disabling themselves for a few seconds mid corner and rearming when upright.

[scracha]

This question comes up reasonably often; Jim2 has mentioned some test results indicating that bikes can, in fact, out-brake cars in the wet and the dry.

I'm fairly sure that actually doing so takes balls and skill, though. It's easy to stomp on the brake pedal in a car, particularly one with ABS, but hauling a bike to a quick controlled stop is a maneuver requiring care and precision.

Exactly. ALL bikes should have ABS if you ask moi.

[skidMark]

1 bike length = 2.3 m
60 kmh = 16.7 m/s
V^2 = 2*f*s
so f = 279/4.6
or f = 60 m/s/s ie 6 g.

That is 6 times what is physically possible, so stop talking crap SM.

What the feck are you on about.

want me to show you?

So what it's meant to take over 12 metres to stop from 60 kph?

Sorry is there no traffic where you are from?

And a 2.3 metre long bike? hang on, last i checked i didn't ride a chopper.

[jrandom]

What the feck are you on about.

You're not that dumb. You know about the gravitational acceleration constant, how '1G' is defined, right? That's about as good as bike tyres get in terms of accelerations they can keep sticking under.

Working out what acceleration a particular stopping distance equates to is straightforward, and the stopping distance you propose equates to six times the braking performance of bike tyres.

No, I don't think you can stop in a bike length from 60kph. That's pure bollocks. And Jantar was being generous with his 'bike length' - would you prefer your statement to sound even stupider if we lower that number?

...

Actually, come to think of it, I nominate you for the 'King of the Shyte Talkers (http://www.kiwibiker.co.nz/forums/showthread.php?t=72171)' award.


want me to show you?

Who do you plan on borrowing a bike from to show him with?

[sAsLEX]

However a car with modern ABS can (again, not will) outbrake a bike without ABS. It all comes down to reaction time and driver/rider ability.

An F1 car can outbrake a bike without touching the brakes.




One tip, which will no doubt be contested, don't cover your brake with 2 fingers. All or nothing.


Why?

I only use two fingers for braking and that is plenty.

[koba]

Another factor to think about its a sportsbike (and others, I guess) needs to load up the front tyre to swing some weight on it before actually biting in to the real braking, perhaps this means that a car may initially outbrake a bike by alot but possibly be reeled in a bit afterwards depending on bike/car/rider/driver.
Just an idea.

[marioc]

http://www.youtube.com/watch?v=7Oz44oGaI4c
I thought bikes would outbrake cars but then I dont know much at all!
btw fifth gear? what a fuckin rip off of top gear.


Actually its not a rip-off at all and has been around just as long.
At least you get a female mmmm Vicki! and boy can she drive.
Better show than top gear anyday

[The Stranger]

Why?

I only use two fingers for braking and that is plenty.

Two finger brakers frequently forget to drop the throttle in an emergency. It's all well and good in normal braking, but I am referring to a panic stop.

We even had a riding instructor attending RRRS doing this in the weekend i.e. he was taking an exceptionally long distance to stop and when he finally pulled the clutch in the engine RPM shot up - he screwed this up several times. A hard habit to break. They all say they wont do it in an emergency, but we see it so frequently that I really don't believe them.

Better control, dexterity and modulation of the brakes as less effort is required.

Under very heavy braking, on many bikes you can get the lever to the bars, but if you have 2 fingers in the way, sorry, you just increased your stoping distance. Sure modern bike with a well maintained brake system it isn't likely to happen, though still well could under some circumstances.

There is little gain in time to get on the brakes by having 2 fingers there all the time, most of the time lost is processing the situation.

[sAsLEX]

Better show than top gear anyday

Rubbish. When did they drive to the North Pole or France?

[jrandom]

Under very heavy braking, on many bikes you can get the lever to the bars, but if you have 2 fingers in the way, sorry, you just increased your stoping distance. Sure modern bike with a well maintained brake system it isn't likely to happen, though still well could under some circumstances.

Point in case - Betty's brakes fade badly over the course of a 20-minute track session. On the first lap at Taupo I'm two-fingering into the hairpin; on the last lap I'm smooshing the lever back to the bars with a full fist; if I two-fingered it I'd crush my other two fingers.

For those as have mentioned braided lines, that's where they come in handy - avoiding fade. Cool fresh brakes won't perform noticeably differently between rubber and steel hoses, but after everything starts working at the limit and getting smoking hot, it's an entirely different matter. Well, so I've been told, anyway. I'll get a set in due course and see for myself.

If you never ride on the track or at quick-to-fast pace on the road, I guess braided lines would be a waste of time, though.


There is little gain in time to get on the brakes by having 2 fingers there all the time, most of the time lost is processing the situation.

Agreed. Does anyone actually ride with index and middle fingers off the throttle all the time? That seems pretty awkward to me. Surely one can open one's hand and grasp the brake lever in no more time than it takes to see and assess a situation.

And, yes, I can't see why you wouldn't go for the full grab in an emergency stop.

Weirdest braking behaviour I've ever seen: braking with the middle, ring and pinky fingers while leaving the index finger wrapped around the throttle.

:crazy:

[sAsLEX]

Agreed. Does anyone actually ride with index and middle fingers off the throttle all the time? That seems pretty awkward to me. Surely one can open one's hand and grasp the brake lever in no more time than it takes to see and assess a situation.

And, yes, I can't see why you wouldn't go for the full grab in an emergency stop.

Weirdest braking behaviour I've ever seen: braking with the middle, ring and pinky fingers while leaving the index finger wrapped around the throttle.

:crazy:

Yip I do nearly all the time.

Yeah a few of the racers do this with the outside three fingers....

[Gubb]

Pardon? Is it really a legal requirement that a bike can stop in 4.6 meters from 50 kmh? Since when is it a requirement that a bike must break all the known laws of physics?

My bad, i've obviously got my wires crossed somewhere.

[imdying]

Point in case - Betty's brakes fade badly over the course of a 20-minute track session. On the first lap at Taupo I'm two-fingering into the hairpin; on the last lap I'm smooshing the lever back to the bars with a full fist; if I two-fingered it I'd crush my other two fingers.Pazzo shorties yo! :yes:

[Mikkel]

One tip, which will no doubt be contested, don't cover your brake with 2 fingers. All or nothing.

I would agree with that. While you can brake on a modern sportsbike quite comfortably with just one or two fingers you loose a lot of feeling with the brakes. More finger -> less effort -> less strain -> higher sensitivity and precision.


Who do you plan on borrowing a bike from to show him with?

Morcs should have no problems about lending Mark his bike again - after all he'd have no problem riding someone else's bike without a license.


An F1 car can outbrake a bike without touching the brakes.

Well, seeing as F1 cars generate a huge amount of downforce - that force has to come from somewhere and that manifests itself in a huge amount of drag. IIRC F1 cars can brake at up to 5-6G...


Weirdest braking behaviour I've ever seen: braking with the middle, ring and pinky fingers while leaving the index finger wrapped around the throttle.

Only explanation I could see for this would be to maintain some grip of the throttle while having a fair amount of precision on your brake. I wouldn't recommend it though - let your slipper clutch do the work and don't worry about blipping the throttle while braking...

[YellowDog]

With my drums all round, I should probably double that.

I believe that a bike will easily out brake an average car.
Yes, a brand new fat tyred ABS Motorbike on a dry straight road can easily out-break a 30 year old 5 litre Holden with bald tyres.

No problem!

[Dak]

Well it's not hard really i made morcs rvf400 with "wooden brakes" stop in a bike length from 60kph in a carpark after being on it 30 seconds.

Can do that same on a zxr....

Takes a fair amount to lock a front wheel, ive had front wheels start locking and skidding and try tuck under etc.... the trick it to keep strong arms to keep the bars straight....once its crooked and it tucks, you are screwed.

In saying this though i do alot of stoppies, so i have practised braking alot.

................BULLSHIT!...................

[mowgli]

With my drums all round, I should probably double that.

Drums, huh? Stink!

[henry]

Never read so much bullshit.

All other things being equal, a car will out brake, and out corner, a bike because it has greater contact with the road.

[mowgli]

Never read so much bullshit.

All other things being equal ...

But that's just it - bikes and cars are not equal!

[Weaver]

Never read so much bullshit.

All other things being equal, a car will out brake, and out corner, a bike because it has greater contact with the road.

Its the same thing that helps you accelerate faster than a car. The weight of the bike vs the car. 180kgs will be easier to pull up than 1200kgs

[Disco Dan]

It's interesting reading everyones opinion on this thread...

I challenge any one of you to come down to AWNMR this evening so we can watch people new to riding, outbreak all the posers! Why? Because riders that attend AWNMR are practicing - it's a bit like wanking, a 'dry run' before doing the 'real thing'.

When I first organised AWNMR it took me a long time to stop, why? because my bike was heavy? nope. Because my breaks where bad? nope. Because I did not have the confidence and the skills/knowledge to complete an emergency braking maneuver safely.

I have personally seen many a 'new' rider out breaking self proclaimed 'experienced' riders simply because they have better skills and more practice after attending AWNMR.

...Listen to The Stranger - he knows what he's talking about!

[nodrog]

superbike vs supercar

http://www.youtube.com/watch?v=ZZKRphfVHqI&feature=related

[henry]

I know I'm probably wasting my breath and shouldn't get into a pissing match over this but...

A vehicles weight, or inertia, doesn't significantly alter is braking performance. The dominating factor is the friction between the road and the tyres. Cars have a bigger contact patch so can apply a greater stopping force to the road.

In a corner it's all about sideways force before the tyres slip. On a bike it is a little over 1G. Cars can handle way more than that.

[Grub]

I believe that cars do in fact stop better than a bike due to coefficient of friction and all that ... but I like this story better ...

The McLaren M10A CanAm car could do 0-160kmh-0 in 6.3 secs ... way cool.

[Mikkel]

superbike vs supercar

http://www.youtube.com/watch?v=ZZKRphfVHqI&feature=related

Nice video :niceone:


A vehicles weight, or inertia, doesn't significantly alter is braking performance. The dominating factor is the friction between the road and the tyres. Cars have a bigger contact patch so can apply a greater stopping force to the road.

In a corner it's all about sideways force before the tyres slip. On a bike it is a little over 1G. Cars can handle way more than that.

Well, you ALMOST got that right. The size of the contact patch is, without going into meaningless detail, determined by only two factors: the weight of the vehicle and the tyre pressure. (The area is equal to the weight of the vehicle divided by the tyre pressure.)

There is one factor that makes it harder for a bike to utilise it's braking potential to the same level as a car: stability. Whether it be lateral or longitudinal.
If you brake too hard you'll end up doing a stoppie which is not ideal. (conservation of angular momentum around the front wheel...).

Cars cornering at more than 1G only happens due to down force - AFAIK there hasn't been made a tyre with a coefficient of friction higher than 1.00 yet. (so that should make it a little LESS than 1G for a bike)


Never read so much bullshit.

Well, take solace in the fact that at least you contributed :p

[Morcs]

Cars will always outbrake a bike with skilled drivers.

Anyone see the top gear episode - 1098 versus meircegulago? the duc got wasted under braking.

And actually mark, cars can corner faster than bikes. Shit load more grip and downforce.

[henry]

Well, you ALMOST got that right. The size of the contact patch is, without going into meaningless detail, determined by only two factors: the weight of the vehicle and the tyre pressure. (The area is equal to the weight of the vehicle divided by the tyre pressure.)


You missed the third and probably most important factor. The car has four flat wide tyres and the bike has two curved tyres.

[Monty69]

I recently watched a documentry about supercars and sportsbikes doing 0-100-0 times. The sportsbikes were generally much faster in acceleration but under brakes the cars would gain the time back. So cars can out brake a bike.

[YellowDog]

Hey Dan. Can you tell me where you hold AWNMR?

May be interetsted in going along.

[PrincessBandit]

In that Mission Impossible movie on the Speed Triple (yummy) Tom (weirdo) Cruise stopped from god knows how fast on the front wheel while pulling a gun out of his pocket and then spun it around (while still doing before mentioned stoppie) and shot the baddie.

Hollywood is so full of crap - every motorcyclists knows to keep both hands on the bars when doing stoppies at 160.

You're just jealous of yummy Tom's exceptional stunt man skills.



(p.s. yes I was taking the yoo-rine btw)
and while i am sure lots of riders only use the 2 finger braking application, i was told at the bhs course to always use all (Ripper Roo92 got told off for only using 2 fingers!)

[AllanB]

Well stunt man was not what I was thinking - but it rhymed with stunt ;)

I bet you lot would stop pretty fast for this traffic gal.

[cowboyz]

http://www.youtube.com/watch?v=7Oz44oGaI4c
I thought bikes would outbrake cars but then I dont know much at all!
btw fifth gear? what a fuckin rip off of top gear.

that 1098 looks nice. Loving the wheelie on the last corner.
If you are going to spend $150000 you might as well buy something you can have some fun on.

[rocketman1]

I guess at the end of this I have learned one thing and that is that I should attend a Course that teaches me How to brake.
Braking over and over in controlled conditions must improve your distances.
It is something that bike clubs should consider running at track days maybe.

[Subike]

A lot of information in this thread,
good arguments from all involved
I have had to rethink my own views upon this subject and say that my first post is wrong.
I guess that in the perfect situation that a bike may be better, but this world is not perfect, so that situation may never appear.
I now think that I may look at my following distances in heavy traffic and allow a bit more room for movement, or keep escape routes more in mind.
Thanks all posters for some awsome information, good links, good debate.

[scracha]

http://www.youtube.com/watch?v=7Oz44oGaI4c
I thought bikes would outbrake cars but then I dont know much at all!
btw fifth gear? what a fuckin rip off of top gear.

BBC cancelled top gear. Channel 5 then took most of the top gear staff and created fifth gear. BBC realised the "new format" was a good one and reintroduced top gear. So basically the new top gear is a fuckin rip off of fifth gear.

[henry]

I have had to rethink my own views upon this subject and say that my first post is wrong.
...
I now think that I may look at my following distances in heavy traffic and allow a bit more room for movement, or keep escape routes more in mind.
Thanks all posters for some awsome information, good links, good debate.

That's what these forums are for. To learn from people with more knowledge and / or experience. The worrying thing is how many idiots still think they know better.

Good on you.

[Mikkel]

You missed the third and probably most important factor. The car has four flat wide tyres and the bike has two curved tyres.

No I am very much aware of the difference in profile between cars and motorcycles. I happen to own one of the former and two of the latter.

What you fail to realise is that the profile of the tyre has (almost) no impact upon the size of the contact patch - only the shape. Besides the size of the contact patch is not what determines the amount of traction you have available. The only thing that matters in relation to traction is the force on the wheel (the weight on the wheel if you want) and the coefficient of friction.

If you don't like it I suggest you take it up with Dr. Isaac Newton.


I bet you lot would stop pretty fast for this traffic gal.

Ah the good old anti-speeding campaign from back home :D

[The Pastor]

you look at the you tube video of the bike vs the lambo on the race track, you can see how much longer it takes to slow a bike vs teh car.

[Mikkel]

you look at the you tube video of the bike vs the lambo on the race track, you can see how much longer it takes to slow a bike vs teh car.

Indeed - but while the 1098 might not be your average bike the lambo is about as far a cry from an average car as you can possibly get. I think you'll find a slight difference on the price tags as well... (besides, I would personally like to have them do all 3 exercises at least 10 times and then compare the averages).

I'd still put my money on your average motorcycle (road-bike, of course) being able to out brake your average family car - and most definately just about any 4x4. That is provided the pilot is not a complete tosser of course in which case you'll end up the way I have on a couple of occasions now. :rolleyes:

Generally speaking bikes have good brakes compared to their weight and unless you have a gross disregard for your own health you take some interest in fitting decent tyres to it. The same cannot be said for most cars out there.

[The Stranger]

I'd still put my money on your average motorcycle (road-bike, of course) being able to out brake your average family car.

So what do you have in mind as an average car and an average motorcycle?

[jrandom]

I'm pretty sure my V6 Camry with ABS wearing Firestone something-or-others can outbrake the hell out of my GSX1400 wearing Pilot Road 2s.

:confused:

In fact, I'd be quite happy to set up a test of that.

[nodrog]

Indeed - but while the 1098 might not be your average bike the lambo is about as far a cry from an average car as you can possibly get..

they are both the top of the range in their respective fields.

at the other end of the spectrum, i would put money on a Daihatsu Mira outbraking a GN250.

[Mikkel]

So what do you have in mind as an average car and an average motorcycle?

Good point really. I'm not even going to suggest an average motorcycle on here - someone is bound to take offense.

Let's say something from the mid to late nineties that weighs around the 200-250 kg mark, have a two-pot caliper disc brake on the front and a single-pot caliper on the rear.

As for the car, take a middle class family sedan from the same period with a weight of about 1100-1300 kg, disc brakes on the front and drums on the rear.

I suspect that the main difference would be the tyres.

[moT]

bikes do stop faster its just up to rider ability

[The Pastor]

the only way to know is to set up some tests _b

[Mikkel]

the only way to know is to set up some tests _b

Test it on the next guy that tail gates you. If he hits you - you won!

[moT]

Test it on the next guy that tail gates you. If he hits you - you won!

you have to factor in reaction time otherwise its a unfair test

[henry]

the only way to know is to set up some tests _b

Plenty of people have (scroll up) and the car always wins.

[marty]

What you fail to realise is that the profile of the tyre has (almost) no impact upon the size of the contact patch - only the shape. Besides the size of the contact patch is not what determines the amount of traction you have available. The only thing that matters in relation to traction is the force on the wheel (the weight on the wheel if you want) and the coefficient of friction.






I suspect that the main difference would be the tyres.

so is it the tyres, or the weight/coefficient of friction that makes difference?

lets see some proof of what you're saying.

[Mikkel]

you have to factor in reaction time otherwise its a unfair test

That was kinda the point behind my not-so-serious post. And the point is of course that it is unfair to the person in front of you to sit closer than your reaction time allows for... And a lot of people do exactly that.


so is it the tyres, or the weight/coefficient of friction that makes difference?

lets see some proof of what you're saying.

I don't follow the first bit of your post. The tyres and road surface - all of their properties (e.g. pressure, temperature, etc) - are what determines the coefficient of friction.

Weight is divided out in the equation since more weight equals more normal force, but also more inertia. More weight will be harder on the tyres and brakes though...

Proof of what I am saying. So what do you suggest? Personally I would suggest *you* go and get a good book on classical mechanics and when you're done with that I doubt you'd feel any need for me to backup what I have been claiming here.

[mowgli]

A vehicles weight, or inertia, doesn't significantly alter is braking performance. The dominating factor is the friction between the road and the tyres. Cars have a bigger contact patch so can apply a greater stopping force to the road.


What you fail to realise is that the profile of the tyre has (almost) no impact upon the size of the contact patch - only the shape. Besides the size of the contact patch is not what determines the amount of traction you have available. The only thing that matters in relation to traction is the force on the wheel (the weight on the wheel if you want) and the coefficient of friction.

Henry is correct - when you do the sums to calculate decelerative force mass cancels out. You are left with gravity and friction. Since gravity is the same for both the defining factor is friction. If you assume no wheel lock up then it all comes down to braking efficiency.

Mikkel is also correct because mass comes back into play when you consider energy. Ie ability of the brakes to convert kinetic energy into heat.

Bikes have fewer brakes but less energy to dissipate. Cars have more brakes but more energy. The winner all depends on what you consider average. I wouldn't like to pick it.

[imdying]

so is it the tyres, or the weight/coefficient of friction that makes difference?As they both influence each other, it would have to be both.

[*caution*]

Henry is correct - when you do the sums to calculate decelerative force mass cancels out. You are left with gravity and friction. Since gravity is the same for both the defining factor is friction. If you assume no wheel lock up then it all comes down to braking efficiency.

Mikkel is also correct because mass comes back into play when you consider energy. Ie ability of the brakes to convert kinetic energy into heat.

Bikes have fewer brakes but less energy to dissipate. Cars have more brakes but more energy. The winner all depends on what you consider average. I wouldn't like to pick it.

And Friction between the tires and the road is dependant on mass, (along with a few other things), in theory for the same mass, and rubber and road total friction is the same no matter the contact patch, (seems odd but if you try the calculations its true, because as contact area reduces for the same mass average pressure on that patch increases, friction is a function of pressure) but then the coefficient of friction for the rubber is not constant, it changes with temperature, so the calculations start to become very complex, the straight answer is yes a motorbike can outbrake a car, but a car can also outbrake a motorbike, a better questions is can X motorbike outbreak Y car.....

Experiments are always fun though!!

[moT]

Y^= Bo + By X which means that the total variation / total variation - unexplained variation/ total variation = explained variation /total variaation

which gives you the R2 regression

[sAsLEX]

Y^= Bo + By X which means that the total variation / total variation - unexplained variation/ total variation = explained variation /total variaation

which gives you the R2 regression

Which explains why Rossi et al take their left foot off when braking....... duh!:niceone:

[Ixion]

But it doesn't work with a shaft drive, eh.

[jrandom]

I only brake with the bottom half of my wheels.

[Ixion]

And only accelerate with the top half ?

(Actually, that is sort of true. But it doesn't work with a shaft drive, either)

[Deano]

A vehicles weight, or inertia, doesn't significantly alter is braking performance. The dominating factor is the friction between the road and the tyres. Cars have a bigger contact patch so can apply a greater stopping force to the road.
.

And trucks have a huge contact patch, but how far does it take them to stop ?

[avgas]

6 of 1 half a dozen of the other.
Both can out brake each other.
It all complete depends on the situation.
I have had a bike stop instantly and a car slide for 40m. And vice versa. Generally you should not drive and ride where you can not see your average stopping distance. Always look for an exit rather than expecting your vehicle to stop immediately.

[koba]

And trucks have a huge contact patch, but how far does it take them to stop ?

Good point,
Farken ages when fully laden. Thats why I don't understand the idea that weight, or inertia doesn't significantly effect overall braking performance - ever tried braking with a trailer-load of gravel?

[avgas]

Good point,
Farken ages when fully laden. Thats why I don't understand the idea that weight, or inertia doesn't significantly effect overall braking performance - ever tried braking with a trailer-load of gravel?
Its actually simpler than you think - take a big rock and move it (ARGGHHHHHHHHGHGHGHHHGHGHGH!!!!) so its moving at constant speed. now take a small rock and move it as the same speed (weeeeeeeeee!) now get them rolling at that speed and let them go. While the small rock travels a good distance the big rock rolls into and through the neighbors fence.

[koba]

Its actually simpler than you think - take a big rock and move it (ARGGHHHHHHHHGHGHGHHHGHGHGH!!!!) so its moving at constant speed. now take a small rock and move it as the same speed (weeeeeeeeee!) now get them rolling at that speed and let them go. While the small rock travels a good distance the big rock rolls into and through the neighbors fence.

Yeah I got that, that is the way my brain thinks but above are comments that somehow that aint the case.
Leafves me a bit confused, as usual.

I think I may try a few tests, I have always wanteed to know how the braking of my two cars compares, maybe I should chuck the bikes into the test too....

[Mike748]

Nah .......
(wait for the totally ill informed opinion) ....
it's the stability and lower COG in a car that makes the difference, as long as you load the cars front brakes up you can get better stopping cause it won't stoppie!!!:yes:

[Mikkel]

Nah .......
(wait for the totally ill informed opinion) ....
it's the stability and lower COG in a car that makes the difference, as long as you load the cars front brakes up you can get better stopping cause it won't stoppie!!!:yes:

:clap: Yes! :yes:

...given that your tyres have enough grip, your brakes are good enough and you have skills.

[koba]

right but mass of the vehicle MUST surely make a difference...

[Mike748]

Mass does make a difference, just like tyres and brakes.
The problem with trucks is, tyres are designed for high k's, suspension is designed to support heavy loads and vehicle chasis is designed for weight distribution, so getting the transfer of energy to the road is way harder than a car or bike.
With trucks primarily designed to haul at low cost you cannot expect progressive performace braking.

(I know this is a generalisation and I'm not including the big modern long haul rigs in this)

Have driven some HT vehicles where the harder you push the brake the faster you go.:eek5:

[Mikkel]

Truck tyres are pretty damn expensive - thus they run a hard compound to enable a longer tyre life. This would be part of the explanation at least.

[avgas]

right but mass of the vehicle MUST surely make a difference...
Ah now you get to the confusing parts.
Rather than me type out the static/dynamics 101 i think i may be better for you to do some research on this on you own time. Basically some key words i recommend you google would be.
Momentum
Friction
Vectors
Rotational force
Weight (g-force if you wish)
If you read these topics up till you get to the differential elements (dy/dt or "s" terms in some books in some texts) it should give you a basic understanding of why this is not so black and white.

[NighthawkNZ]

You're not that dumb.
:gob: bwahahahhaha.. im sorry but..

[crazybigal]

man you talk some shit!!
2m at 60k id love to see that! you would be over the bars and flying!


Well yeah i mean i can stop a bike from 60kph in 2 metres.

That is once reacted andd actually applying brakes.

But i have been in some cars that stop pretty bloodey fast.

As in hit the brakes and its stopped. 120 kph - 0 kph in err pass, a bloodey short distance thats for sure.

[koba]

Ah now you get to the confusing parts.
Rather than me type out the static/dynamics 101 i think i may be better for you to do some research on this on you own time. Basically some key words i recommend you google would be.
Momentum
Friction
Vectors
Rotational force
Weight (g-force if you wish)
If you read these topics up till you get to the differential elements (dy/dt or "s" terms in some books in some texts) it should give you a basic understanding of why this is not so black and white.

Im not a huge reader I may have a quick gander at some googled info but I think I need to put the motor back in my car for and interesting experiment, It has very little to do with what we are talking about but it should be interesting to objectivley test the braking distance of my two cars, a disk braked beetle and a full drum lightened beach buggy....

All this just got me thinking : I wonder which will stop quicker..

What do people think?
Which will stop in a shorter distance averaged over 3 or more goes, same day, sameish fuel load etc etc,


One is standard 1969 VW Beetle Disc brake front and I think 3 inch drums on the back
185/15 tyres (a bit shabby) on the front
205/15 Gr200 Enduros on the back.
Weight unknown, est 800kg.
while the other is

a fibreglass beach buggy with 4 wheel drums (3in Front 2 in rear I think) Sill volkswagen based, 14 inches shorter wheelbase.
165/15 tyres (nice CONTIs!) on the front,
205/15 Supercats on the back
Weight is measured 450kg without fuel or passengers.


When I am closer to getting this done (engine in the beach buggy instead of under a tarp in the driveway!) I may start a poll or somthing, may also add in some bikes and/or other cars. just for fun :)

[Monty69]

In the end, factual emergency stopping distance recordings show, cars CAN outbrake bikes. Obviouisly a 1964 vw beetle wont out brake a R1 but modern sportscars will outbrake a sportsbike by a significant margin. :done:

[Drew]

It seems pretty simple to me, there are basically only two contributing factors in braking for cars, momentum/friction. A bike has three large and one smaller force to overcome, momentum/friction/gravity/mass deviation(not sure if that's the right term for it, I'm talkin about the bike trying to screw sideways once the weight comes off the rear tyre.)

[Mikkel]

One is standard 1969 VW Beetle Disc brake front and I think 3 inch drums on the back
185/15 tyres (a bit shabby) on the front
205/15 Gr200 Enduros on the back.
Weight unknown, est 800kg.

That's not a standard beetle! :no:


The problem about mechanics is that people think they can understand them without ever having spent 30 minutes studying it. And then they get pissy and demand that you explain it to them in 5 minutes. Which you obviously can not since they don't have the necessary prerequisites - which in turn means that you suck at explaining mechanics. :rolleyes: Being an academic is neither gratifying nor respected these days.

I studied classical mechanics during the first year of uni - we had two 2 hour lectures, a 2 hour problem solving session and a written hand-in every week for two semesters of 13 weeks each. Then we had a couple of months to prepare for the oral exam. I got an A+ and then worked for 2 years as an assistant teacher, running a 2 hours problem solving session and correcting written hand-ins every week for 4 semesters of 13 weeks.

All that said, I shall be the first to admit I don't know everything about mechanics and that I'd be reluctant to try and solve any complex 3-dimensional problem. However, I would like to think that I have an, if only slightly, better understanding than Joe Average.

And now I think it's time to go have a beer! Another frustrating week of academia draws to a close and I'm looking forward to the weekend - not least to have my girlfriend back from her holiday. :apint:

[cowboyz]

I studied classical mechanics during the first year of uni - we had two 2 hour lectures, a 2 hour problem solving session and a written hand-in every week for two semesters of 13 weeks each. Then we had a couple of months to prepare for the oral exam. I got an A+ and then worked for 2 years as an assistant teacher, running a 2 hours problem solving session and correcting written hand-ins every week for 4 semesters of 13 weeks.



Guess that makes it even more embarassing when your wrong then huh?

[Mikkel]

Guess that makes it even more embarassing when your wrong then huh?

Not really. What do you do for a living if I may ask?

[The Stranger]

Not really. What do you do for a living if I may ask?

BWAHAHAHAHA, give it up.

[jrandom]

Conveying understanding to others is the true sign of having mastered a subject.

In my experience, having to make excuses for an inability to explain things clearly indicates that one doesn't quite have a grasp of what one is talking about.

[cowboyz]

Not really. What do you do for a living if I may ask?

I am a greenskeeper.......


BWAHAHAHAHA, give it up.

You know where this is going huh?

[jrandom]

What do you do for a living if I may ask?

You do realise that the appeal to authority is the saddest of the classic logical fallacies, don't you?

[cowboyz]

FFS jrandom! I already said I was just a greenskeeper and you start using big words like that!!!!!!!

[Subike]

After reading this lot of junk, truth, facts and other gobbly gook
I have come to a conclusion.
The average driver of an average cage when pitted against
The average rider of an average Bike
will not win the Braking battle.
I think that with the superiour ( tounge in cheeck comment) awareness of the Biker, compared to the complacent awareness of a cage driver,
A bike will out brake a car every time.
Thats the practical side of it in my opinion, not the Factual side where the bike seems to loose out.
WWWEeeeeeeeee.......scrreeeeech.....thump! Oh Dear I didnt see you, sorry!

[Mikkel]

I am a greenskeeper.......

If so I wouldn't presume to tell you that you were wrong if you told me how to "keep the greens" - if you know what I mean.


Conveying understanding to others is the true sign of having mastered a subject.

In my experience, having to make excuses for an inability to explain things clearly indicates that one doesn't quite have a grasp of what one is talking about.

I agree - however explaining things to people who only pretend to listen and won't pay attention for more than 5 minutes is not possible. At least not if we're talking anything technical.

Would you be able to explain to me in 5 minutes how to construct a database to such a detail that I would be able to understand all of the underlying principle? (Or for the sake of argument, if you should doubt my ability to grasp the subject, someone else.)

I'll start my stopwatch when I post this.

[Ixion]

You do realise that the appeal to authority is the saddest of the classic logical fallacies, don't you?

Sez who ?

[Mikkel]

You do realise that the appeal to authority is the saddest of the classic logical fallacies, don't you?

You do realise that jumping to conclusions is the trademark of the narrowminded, don't you?

[The Stranger]

Sez who ?

jrandom - post 121

[cowboyz]

If so I wouldn't presume to tell you that you were wrong if you told me how to "keep the greens" - if you know what I mean.


I agree - however explaining things to people who only pretend to listen and won't pay attention for more than 5 minutes is not possible. At least not if we're talking anything technical.

Would you be able to explain to me in 5 minutes how to construct a database to such a detail that I would be able to understand all of the underlying principle? (Or for the sake of argument, if you should doubt my ability to grasp the subject, someone else.)

I'll start my stopwatch when I post this.

Firstly, I never said you were wrong - even though you are.

Reality is a fantastic way of proving theory wrong.

The question at hand is can a motorbike outbrake a car. To compare apples with apples you have to take out all the "other" factors (reaction time, awareness etc)

I am not going to pull my pants down in public and stand on a soapbox as you have done because it is not my style. What I will do is agree with the mulitude before me who have said that a car will outbrake a motorbike.

[The Stranger]

Would you be able to explain to me in 5 minutes how to construct a database to such a detail that I would be able to understand all of the underlying principle? (Or for the sake of argument, if you should doubt my ability to grasp the subject, someone else.)


I think you may have trouble explaining it to an academic, but I would put money on the greens keeper - so long as he hasn't been inhaling too much of his green.

[Mikkel]

Firstly, I never said you were wrong - even though you are.

Reality is a fantastic way of proving theory wrong.

The question at hand is can a motorbike outbrake a car. To compare apples with apples you have to take out all the "other" factors (reaction time, awareness etc)

I am not going to pull my pants down in public and stand on a soapbox as you have done because it is not my style. What I will do is agree with the mulitude before me who have said that a car will outbrake a motorbike.

Theory is a fantastic way of predicting - with some uncertainty - how reality is going to behave.

If you don't accept that I would suggest you throw away all of the comforts you enjoy and go live under a rock instead. Science - the entire spectrum of it - is what has given us the resemblance of civilisation that you see today. Science is based on theory confirmed through experimentation.

Indeed sometimes the theory is disproven by experimentation and you have to reformulate either the basics or perhaps just the hypothesis you are testing. If we're talking classical mechanics there are a few hundred years (about 400 give or take) of support for this theory. So I dare say the theory is not wrong - but yes to discuss it you need to make assumptions and simplifications. However, that doesn't mean that the discussion can not be interesting.

Such a discussion came into being as a result of this thread. Now considering this - would you care to enlighten me as to exactly where I was 'wrong'?

[Ixion]

Considerations of modern vehicle braking are not resolvable by classical physics. The forces are more complex than simple frictional mechanics.

Can a motorcycle outbreak a car requires specification of what motorcycle, what car, what road, what rider, what driver, what weather. An MV versus a Ferrari, probably the ferrari. GSXR750 versus Auntie Mabel's Corolla, probably the Gixxer (unless the road is wet) (or Boomer is riding, in which case the bike will outbrake the car, but then crash)

[cowboyz]

Theory is a fantastic way of predicting - with some uncertainty - how reality is going to behave.

Theroy is using variables. Variables, by definition, vary. Sure you can have an educated guess (call it a theory if you like) but experiment is where science comes into its own.
If you don't accept that I would suggest you throw away all of the comforts you enjoy and go live under a rock instead. Science - the entire spectrum of it - is what has given us the resemblance of civilisation that you see today. Science is based on theory confirmed through experimentation.
A little like, penacillin? shall we say?

Indeed sometimes the theory is disproven by experimentation and you have to reformulate either the basics or perhaps just the hypothesis you are testing. If we're talking classical mechanics there are a few hundred years (about 400 give or take) of support for this theory. So I dare say the theory is not wrong - but yes to discuss it you need to make assumptions and simplifications. However, that doesn't mean that the discussion can not be interesting.

Such a discussion came into being as a result of this thread. Now considering this - would you care to enlighten me as to exactly where I was 'wrong'?

Where you went wrong....
First and formost you tried to qualify your staement with a barrage of pant dropping, "I know this and everyone else is too dumb to grasp the concept"

For where I am sitting that was an attempt for credibility. Unfortunately, it doesnt work.

Then there is the whole point that cars CAN outbrake bikes. If you want to dig up all sorts of theroys that "prove" (remembering that nothing is proved on theroy) then by all means, go ahead. But you cant qualify a theroy with "I would explain it but there is no point because everyone else is too dumb to understand it".

It will not change the fact that cars stop faster than bikes.

[cowboyz]

Considerations of modern vehicle braking are not resolvable by classical physics. The forces are more complex than simple frictional mechanics.

Can a motorcycle outbreak a car requires specification of what motorcycle, what car, what road, what rider, what driver, what weather. An MV versus a Ferrari, probably the ferrari. GSXR750 versus Auntie Mabel's Corolla, probably the Gixxer (unless the road is wet) (or Boomer is riding, in which case the bike will outbrake the car, but then crash)

saying. but but but this superbike vs this POS car and taking one offs just doesnt cut it.

Overall, apples for apples - or close enough the car will win.

If anyone wanted to be really argumentative they could argue that $/m of braking performance and incorporate the cost of the vehicles. - but in the real world, it wont actually matter.

[Ixion]

But, by the definition of the question, you are not comparing apples and apples. You are comparing two quite different things.

I suspect that, nowdays, the average car (in so much as such a beast exists - let us assume that we take a random sample of 100 from the motorway at rush hour) ) is capable of out braking the average motorcycle (ditto) . But the average rider is capable of out braking the average driver. Where the two cross over is an imponderable. The question is as meaningless as saying "Are cars faster than motorbikes"

[cowboyz]

But, by the definition of the question, you are not comparing apples and apples. You are comparing two quite different things.

I suspect that, nowdays, the average car (in so much as such a beast exists - let us assume that we take a random sample of 100 from the motorway at rush hour) ) is capable of out braking the average motorcycle (ditto) . But the average rider is capable of out braking the average driver. Where the two cross over is an imponderable. The question is as meaningless as saying "Are cars faster than motorbikes"

true.

The same way you hear about how people "cleaned up" xxxxx on a set of twisties. - only to find out one of them didnt realise they were racing.

The only fair way to do it is side by side where both rider and driver know what is expected of them and either are muppets.

Then the car will win.

Have to spend another 8 years figuring out what is a "fair" contest and what the average bike is and what an average car is.

[marty]

I guess if you pit the pinnacle of each mode - a MotoGP bike and an F1 car.

The F1 would eat the GP bike for braking.

Discuss.

[koba]

That's not a standard beetle! :no:


The problem about mechanics is that people think they can understand them without ever having spent 30 minutes studying it. And then they get pissy and demand that you explain it to them in 5 minutes. Which you obviously can not since they don't have the necessary prerequisites - which in turn means that you suck at explaining mechanics. :rolleyes: Being an academic is neither gratifying nor respected these days.

I studied classical mechanics during the first year of uni - we had two 2 hour lectures, a 2 hour problem solving session and a written hand-in every week for two semesters of 13 weeks each. Then we had a couple of months to prepare for the oral exam. I got an A+ and then worked for 2 years as an assistant teacher, running a 2 hours problem solving session and correcting written hand-ins every week for 4 semesters of 13 weeks.

All that said, I shall be the first to admit I don't know everything about mechanics and that I'd be reluctant to try and solve any complex 3-dimensional problem. However, I would like to think that I have an, if only slightly, better understanding than Joe Average.

And now I think it's time to go have a beer! Another frustrating week of academia draws to a close and I'm looking forward to the weekend - not least to have my girlfriend back from her holiday. :apint:


:shit: Enjoy drinking beer do ya?

Seemed to like mine when you nicked it from the kendogs fidge....

wonk wonk Im so smart blah blah blah blah. :yawn:

I will also admit that I dont understand alot, my earlier posts show as much but I really hate when people get all righteous about what they do know... alot of People WONT listen to you at all if they think you are a condecending prick, bear that in mind when you frustrated that know one wants to hear what you have to say!


Also it IS a standard beetle in all but the tyres and motor, standand tyres on the front and fats on the back, motor is slightly modifed using standard parts, they came out with faster motors than the one in mine tho.
Power aint going to make a difference to my little brake test that I want to perform out of personal interest and not to prove some silly point. :motu:

[koba]

I guess if you pit the pinnacle of each mode - a MotoGP bike and an F1 car.

The F1 would eat the GP bike for braking.

Discuss.

F1 would eat just about anything for baking, truly amazing...

[Trudes]

F1 would eat just about anything for baking, truly amazing...

Really?? Would an F1's muffins be better than Hels'???

[koba]

smarty! :p :woohoo:

[BASS-TREBLE]

Talking about F1 cars......


An average F1 car can decelerate from 100-0 km/h (62-0 mph) in about 17 metres (55 ft), compared with a 2007 Porsche 911 Turbo which takes 31.4 metres (103 feet).[citation needed] When braking from higher speeds, aerodynamic downforce enables tremendous deceleration: 4.5 g to 5.0 g (44.1 to 49 m/s²), and up to 5.5 g at the high-speed circuits such as the Circuit Gilles Villeneuve (Canadian GP) and the Autodromo Nazionale Monza (Italian GP). This contrasts with 1.0 g to 1.5 g for the best sports cars (the Bugatti Veyron is claimed to be able to brake at 1.3 g). An F1 car can brake from 200 km/h (124 mph) to a complete stop just 2.9 seconds, using only 65 meters (213 ft).[6]

How many bike lengths is 17m?

Source: http://en.wikipedia.org/wiki/F1_cars

[marty]

yes, but there's your comparison for engineering. choose any high end race car, pit it against a high end race bike. the cars would kick the bikes' arses.

quick search - Phillip Island - fastest bike lap (Melandri) = 1.30. fastest car lap 1.24 (and that's only in an old Reynard) - 250cc supercarts are 1.32, even the V8 supercars are 1.33

[The Stranger]

alot of People WONT listen to you at all if they think you are a condecending prick, bear that in mind when you frustrated that know one wants to hear what you have to say!



Mikkel, a condescending prick?
Surely not :gob:

[Mike748]

It doesn't necessarily take a high spec car to get good braking performance. Had a company vehicle once (which we all know are the fastest road cars :laugh:) it was a little Daewoo hatch that could haul to a stop real quick.
(not every corner or the brakes cook)

It also needed it's first brake pad change at 27thou and new disks at 40thou then pads again at 75thou when I handed it on. :innocent:

[koba]

Off the mikkle bashing and back to the topic, some interesting figures, obviously not DIRECTLY comparable but worth a gander.
http://brianrpatterson.blogspot.com/2008/01/abs-brakes-how-good-are-they.html
Bike braking tests for some bikes with ABS ranged from 37.4m (BMW R1200R) to 49.1 (Yamaha FJR 1300)

http://www.wheels.ca/article/32604
Average small car tests, braking distancees ranged from 47.9 metres (Ford Focus SE) to 41.5 metres (Mitsi Lancer GTS)

http://www.nsxprime.com/FAQ/Technical/performancenums.htm
This site puts braking performance of an older Honda NSX at 134 feet (just under 40 meters)

[Mike748]

Nooo ...... don't give me links! I prefer artistic licence interpretations that mislead and confuse, way more entertaining! :lol:

.... err sorry I'll go looksee now.

[koba]

And here is the science bit explained with a bit more of a practical eye, makes sense to me :)

Truck, Scooter Stopping Distance

2/15/2004


name Soman P.
status other
age 40s

Question - A truck and a scooter, both are moving in the same
direction with same velocity. Which vehicle will come to rest first
when the brakes are applied simultaneously?
-----------------
Soman P.,
In an IDEAL situation, provided both vehicles had the same coefficient of friction between
wheels and ground, both would stop in the same length of time. If the truck were 1000 times
the mass of the scooter, the truck would have 1000 times the momentum and 1000 times the
braking force. For constant force, (momentum change)=(force)x(time). The same time works
for both situations.

In a REAL situation, the truck takes much longer to stop. This is because the truck's brakes
cannot exert enough force to keep the wheels from turning. For a scooter, the brakes freeze
the wheels in place. The scooter slides to a halt. For a truck, the brakes only slow the
wheels down. There are several reasons for this. First, the force produced by locking the
brakes in place would damage both the axles and the wheels enough to be dangerous. Second,
the wheels would stop the truck but not the load in the trailer. The material would continue
moving forward, crashing into the front panel of the trailer and possibly breaking through.
This too would be very dangerous. Large trucks and semis are designed to stop slowly.

Dr. Ken Mellendorf
Physics Professor
Illinois Central College
================================================== ===

From:http://www.newton.dep.anl.gov/askasci/phy00/phy00754.htm

[Kickaha]

In a REAL situation, the truck takes much longer to stop. This is because the truck's brakes cannot exert enough force to keep the wheels from turning.

In the real world I've seen many a truck completely lock the brakes up and flat spot tyres in emergency stops

[marty]

for a physics professor, Dr. Ken Mellendorf uses some pretty emotive language.

[Jantar]

Off the mikkle bashing and back to the topic, some interesting figures, obviously not DIRECTLY comparable but worth a gander.
http://brianrpatterson.blogspot.com/2008/01/abs-brakes-how-good-are-they.html
Bike braking tests for some bikes with ABS ranged from 37.4m (BMW R1200R) to 49.1 (Yamaha FJR 1300)

http://www.wheels.ca/article/32604
Average small car tests, braking distancees ranged from 47.9 metres (Ford Focus SE) to 41.5 metres (Mitsi Lancer GTS)

http://www.nsxprime.com/FAQ/Technical/performancenums.htm
This site puts braking performance of an older Honda NSX at 134 feet (just under 40 meters)

Which confirms what has been said again and again. A bike (BMW R1200R) can out brake a car (Mitsi lancer GTS). A car (Mitsi Lancer GTS) can out brake a bike (Yamaha FJR 1300).

It all comes down to rider/driver ability, coefficient of friction of the tyre/road surface and ability of the brake pads/disks to absorb and disipate energy.

[koba]

Which confirms what has been said again and again. A bike (BMW R1200R) can out brake a car (Mitsi lancer GTS). A car (Mitsi Lancer GTS) can out brake a bike (Yamaha FJR 1300).

It all comes down to rider/driver ability, coefficient of friction of the tyre/road surface and ability of the brake pads/disks to absorb and disipate energy.


Damn right!
and lean angle too...
I have had my head hit the rimutaka hill pretty hard trying to scrub of speed in a real hurry!

[koba]

In the real world I've seen many a truck completely lock the brakes up and flat spot tyres in emergency stops


for a physics professor, Dr. Ken Mellendorf uses some pretty emotive language.

Yeah, come to think of it the load probably aint going to push thu the front of the trailer either, I would guess that the trailer would Jackknife around as a result of the continued motion of its loada and weight.

Academics aye..

[moT]

MY GOD this is such a stupid thread how can we expect to answer a question like that there is no specifics.. What type of car? what type of motorcycle? a gp bike will out brake a mini and a porche will out brake a harley!!! if you are talking about bikes and cars in general you will have to find the average braking distance for every type of car and motorcycle and then compare! this is a stupid and irrelevent thread ask a more specific question.

[FJRider]

If you are confident in being able to out brake a car, tail gate them... no worries. IF NOT... BACK OFF a bit. Your choice.

[Mikkel]

Damn, I've been out of the loop at the wrong time...


Considerations of modern vehicle braking are not resolvable by classical physics. The forces are more complex than simple frictional mechanics.

Considering the general behaviour of motorvehicles we can neglect both quantum physical and relativistic effects - as such classical mechanics will describe the situation fully and adequately.


Where you went wrong....
First and formost you tried to qualify your staement with a barrage of pant dropping, "I know this and everyone else is too dumb to grasp the concept"

For where I am sitting that was an attempt for credibility. Unfortunately, it doesnt work.

Then there is the whole point that cars CAN outbrake bikes. If you want to dig up all sorts of theroys that "prove" (remembering that nothing is proved on theroy) then by all means, go ahead. But you cant qualify a theroy with "I would explain it but there is no point because everyone else is too dumb to understand it".

It will not change the fact that cars stop faster than bikes.

No, you are wrong. My pants dropping wasn't an attempt at ridiculing anyone else. I only tried to convey a bit of the frustration that derives from trying to explain something and being met with a "I don't fucking care about what makes sense, wanker!" There is a difference...


:shit: Enjoy drinking beer do ya?

Seemed to like mine when you nicked it from the kendogs fidge....

wonk wonk Im so smart blah blah blah blah. :yawn:

I will also admit that I dont understand alot, my earlier posts show as much but I really hate when people get all righteous about what they do know... alot of People WONT listen to you at all if they think you are a condecending prick, bear that in mind when you frustrated that know one wants to hear what you have to say!


Also it IS a standard beetle in all but the tyres and motor, standand tyres on the front and fats on the back, motor is slightly modifed using standard parts, they came out with faster motors than the one in mine tho.
Power aint going to make a difference to my little brake test that I want to perform out of personal interest and not to prove some silly point. :motu:

Mate, if that is indeed the case I can only say I am sorry and would have hoped that you had sent a PM a while back instead of holding a grudge. It certainly was never my intention to filch you beers... (I'll send you a PM followng this.)

Regarding the beetle - my only point was that the tyre sizes sounded a bit off for a 1969 model. Also - did the beetle of that year indeed have disc brakes on the front?


Question - A truck and a scooter, both are moving in the same
direction with same velocity. Which vehicle will come to rest first
when the brakes are applied simultaneously?
-----------------
Soman P.,
In an IDEAL situation, provided both vehicles had the same coefficient of friction between
wheels and ground, both would stop in the same length of time. If the truck were 1000 times
the mass of the scooter, the truck would have 1000 times the momentum and 1000 times the
braking force. For constant force, (momentum change)=(force)x(time). The same time works
for both situations.

In a REAL situation, the truck takes much longer to stop. This is because the truck's brakes
cannot exert enough force to keep the wheels from turning. For a scooter, the brakes freeze
the wheels in place. The scooter slides to a halt. For a truck, the brakes only slow the
wheels down. There are several reasons for this. First, the force produced by locking the
brakes in place would damage both the axles and the wheels enough to be dangerous. Second,
the wheels would stop the truck but not the load in the trailer. The material would continue
moving forward, crashing into the front panel of the trailer and possibly breaking through.
This too would be very dangerous. Large trucks and semis are designed to stop slowly.

Dr. Ken Mellendorf
Physics Professor
Illinois Central College
================================================== ===

From:http://www.newton.dep.anl.gov/askasci/phy00/phy00754.htm

I'm getting a bit curious - where is the difference between what you are quoting and what I said earlier in this thread? :scratch:

[scracha]

If you are confident in being able to out brake a car, tail gate them... no worries. IF NOT... BACK OFF a bit. Your choice.

Doesn't matter whether you can out-brake them. If you're up their arse you'll smack into the back of them before you've even thought about grabbing a handful of brake lever.

[Mike748]

Doesn't matter whether you can out-brake them. If you're up their arse you'll smack into the back of them before you've even thought about grabbing a handful of brake lever.

+1

:corn:
(anticipates thread shift to swerving and bike position on the road)

[imdying]

Ques. Do I have stay more than 10 car lengths behind a van/car at say 100kmh , can I safely stop in time?The real question.

2 second gap, 4 in the wet.The real answer.

Whilst it has been a lovely thread, really, this is all the OP needs to know. You follow too close, have a nana moment, suddenly someone else is wiping your arse for the next 50 years. Play safe kids :yes:

[imdying]

Doesn't matter whether you can out-brake them. If you're up their arse you'll smack into the back of them before you've even thought about grabbing a handful of brake lever.Yep, always remember to multiply the 2 second rules by the number of handles you had at the last pub :yes:

[Biggles2000]

The only thing a typical bike can do better than a average car is accelerate. Your average performance car will on the other hand brake later, corner harder and get the power on faster than any performance bike. The only advantage the bike has is better power to weight ratio. Keep in mind also that the bike has a much higher centre of gravity so it pulls wheelies and stopies which can be a performance limiting factor espcially at relativaly slow speeds.
As far as tyres go, top end sports bike and performance car road tyres seem to last about as long as each other.

[Gixxer peter]

2 second gap, 4 in the wet.???

Hmm... I always wonder why we need to double the gap in the wet??
Surely the vehicle in front of you and behind you are also influenced by the the wet road and will take a longer time to come to a stop, so wont the gap between vehicles be unchanged??

Maybe a problem if the vehicle in front comes to a sudden stop due to crashing in to a statioary object, but other than that???

[Drew]

2 second gap, 4 in the wet.???

Hmm... I always wonder why we need to double the gap in the wet??
Surely the vehicle in front of you and behind you are also influenced by the the wet road and will take a longer time to come to a stop, so wont the gap between vehicles be unchanged??

Maybe a problem if the vehicle in front comes to a sudden stop due to crashing in to a statioary object, but other than that???

That makes sense, but a car can stop considerably better in the wet than a bike, so increasing following distance can only be the smart bet.

[imdying]

Hmm... I always wonder why we need to double the gap in the wet??In the dry, you can hammer the crap out of your brakes, and if it locks, no biggy, just let go and reapply (unless you're mike :rofl:)... I challenge you to have that sort of committment in the wet :yes: Smart people leave bigger gaps in the wet...

[cowpoos]

If you never ride on the track or at quick-to-fast pace on the road, I guess braided lines would be a waste of time, though.


modern brake lines are acctually very very good!! good clean brake fluid and quality aftermarket pads..are all anyone on the road and most people on a race track will even need!!

[cowpoos]

The very stickiest bike tyres have been tested at just under 1G braking performance. That is equal to 38 m from 100 kmh.

The main limiting factor with bikes braking is acctually pitching the machine over on its nose [or popping up in to a stoppie if u prefer]...every other circumstance is rider error!!

[cowpoos]

he was taking an exceptionally long distance to stop and when he finally pulled the clutch in the engine RPM shot up - he screwed this up several times. A hard habit to break. They all say they wont do it in an emergency, but we see it so frequently that I really don't believe them.
.

another tip...unless yuou well schooled at slamming down the gears blipping the throttle etc and using the engine to brake aswell...just pull the clutch in at the start of the emergency braking!! saves you having to slow the inertia of the engine aswell...and theres a lot of weight spinning around in a small engine!

[Drew]

another tip...unless yuou well schooled at slamming down the gears blipping the throttle etc and using the engine to brake aswell...just pull the clutch in at the start of the emergency braking!! saves you having to slow the inertia of the engine aswell...and theres a lot of weight spinning around in a small engine!

Most engines crank spins the same way as the wheels I think Poosey, so as it slows it would increase the forward rolling momentum of the bike. Same as the freestylers doin back flips, they leave the ramp with clutch in at low revs, then rev shit out of it to help rotate the bike backwards, and throttle off to steady it for landing. So letting the revs drop as you brake hard would cause the bike to lift the rear more easily.

All this is totally redundant since by the time you complete the checklist for stopping, your spleen has exploded as your sternham hits the head stock.

Apply the brakes, stand up, and brace yourself. Extra points are awarded if onlookers can hear you yell..."I CAN SEE MY HOUSE FROM HERE", before you hit the ground infront of the car you were too close to.

[cowpoos]

Most engines crank spins the same way as the wheels I think Poosey, so as it slows it would increase the forward rolling momentum of the bike. Same as the freestylers doin back flips, they leave the ramp with clutch in at low revs, then rev shit out of it to help rotate the bike backwards, and throttle off to steady it for landing. So letting the revs drop as you brake hard would cause the bike to lift the rear more easily.

. Very clever theory Bro...but the crank is forward of the bikes theoretical piviot point.

But was not the point I was making besides..I was trying to exclaim that your brakes are slowing the engine inercia down aswell if the clutch is released..and you are not down changing using the engine braking.

[dipshit]

You do realise that the appeal to authority is the saddest of the classic logical fallacies, don't you?

Don't worry, you get these engineer types in all sorts of internet forms talking huge amounts of bollocks on a daily basis as if they are the ultimate authority on everything.

I see engineers in photography forums I hang out in for example, who could talk for ages and ages on pointless technical dribble as if photography could be broken down into science... yet these same engineers couldn't take a decent photo to save themselves.

[Subike]

Most engines crank spins the same way as the wheels I think Poosey, so as it slows it would increase the forward rolling momentum of the bike. .

are you talking about the engines kenetic inertia rotating in a forward direction upon decelleration?
Funny
I thought the engineers sused that out years ago, and the inertia is transfered rearward in IL4s, well Yamaha XS1100s do, as is the engine rotates anticlockwise when viewed from the right hand side if the bike,opposite direction to the wheels.

So thats not an argument


I also agree that using the engine braking under braking can be a learnt skill.
Hell Its easier than using the brakes into ordinary corners, I do it often. And under hard braking It can be done if you practice. Very harsh on the drive train, but then you want everything stopping you when needed .

[Drew]

are you talking about the engines kenetic inertia rotating in a forward direction upon decelleration?
Funny
I thought the engineers sused that out years ago, and the inertia is transfered rearward in IL4s, well Yamaha XS1100s do, as is the engine rotates anticlockwise when viewed from the right hand side if the bike,opposite direction to the wheels.

So thats not an argument


I also agree that using the engine braking under braking can be a learnt skill.
Hell Its easier than using the brakes into ordinary corners, I do it often. And under hard braking It can be done if you practice. Very harsh on the drive train, but then you want everything stopping you when needed .

It was just some bullshit I prattled out for poos' benefit mate. There's no actual thought involved, or anything resembling educated opinion.

The down shift thing is interesting, I dont remember ever doing it in an emegancy situation. And I've had more than my fair share.

[cowpoos]

There's no actual thought involved, or anything resembling educated opinion.
.


Well the was obvious!! :whistle:

I miss our stupid debates for the sake of debating [or was it hearing our own voices??]

[Biggles2000]

I was taught to pull the clutch in under emergency breaking as the ammount of breaking from the motor varies with RPM and can be unpredictable to control. Also as the back wheel comes off the road load its better to be free spinning.
Hey dipshit i'm an engineer, can't spell to save my life but can do maths.

[Drew]

I was taught...

Not having a dig at you or your teacher mate, but I think this a classic case of people being "over taught".

I get a bit wound up when beginers start goin on about counter steering, and other things that take thier mind off what actually matters.

My advice for emergancy stopping to even the most experienced rider is as said in my ealier post. Hit the picks as much as poss', and if it aint lookin good, stand up on the pegs. The last bit is redundant I think, because both times I've hit a car, (one my fault, one not) I just did it without thinkin, as did my dad when someone pulled in front of him.

Keep it simple, the technical shit is just that...shit.

[quallman1234]

Too much too think about, just ride the thing!

[The Stranger]

But was not the point I was making besides..I was trying to exclaim that your brakes are slowing the engine inercia down aswell if the clutch is released..and you are not down changing using the engine braking.


You are right, in some cases.
A good rider on a modern race replica type bike is capable out braking the engine, and lets face it, that's everyone isn't it? Well no, maybe 1 or 2%.
The rest they are better off with the clutch out.

Personally I take Drew’s point, i.e. Keep it simple. That will serve the vast majority much better.

How can you train for an emergency?
Well not too difficult.
What you do in an emergency is what you normally do i.e. what has become instinct.
Practice good habits in normal riding and that is what you will do in an emergency, simple.
The 2 main points I would make are
1) Front brake, unless you are on a cruiser.
2) 4 fingers on the lever, if you normally use 2, guess what you will do in an emergency?
3) Progressive braking. Apply some pressure, as the weight transfers apply more. A short sharp all out grab will probably just lock the front and increase braking distance, or worse.

If practised such that it is "normal" procedure you will do these as a matter of course in an emergency.

[sinfull]

if it aint lookin good, stand up on the pegs.

I was once forced by the courts to attend a defensive driving course, was only in my twenties and no i haven't become more responsible with age !
He was prattling on about emergancy stops and asked what should you do, if a head on was unavoidable, to which i answered * get off * He then proceeded to inform the class that you should stand on the seat and prepare to be catapalted over the car !
I thought then i was waisting my time there and still believe he was a clown !

When you say stand up on the pegs Drew, i presume ya mean spring off em if ya aint all twisted up sideways ?

[Masterchop]

This might answer some of the questions,but might change in the wet.
http://youtube.com/watch?v=ZZKRphfVHqI

[Kickaha]

He then proceeded to inform the class that you should stand on the seat and prepare to be catapalted over the car !
I thought then i was waisting my time there and still believe he was a clown !

You were right he was a clown, in that sort of situation I doubt you'd have time to do it anyway


When you say stand up on the pegs Drew, i presume ya mean spring off em if ya aint all twisted up sideways ?

Standing up on the pegs will supposedly get you clear of the bike when you impact without getting tangled on the handlebars on the way over and may also put you over instead of into whateever it is you're hitting

[dipshit]

and if it aint lookin good, stand up on the pegs.

I was thought this as well and is something I have always had in the back of my mind. If the hit is looking inevitable, stand up, and hopefully you'll go flying over the car, rather than through it.

[cowboyz]

at what point do you decide it is inevitable?

I have brushed my leg and shoulder up against the front of a truck that failed to giveway at a roundabout and made it That take SHITLOADS AND SHITLOADS OF LUCK to pull off but as always I ride to stay with the bike while it is still upright. After the bike is over then it is time to get as far away as possible.
I am not saying all (there is always an exception to the rule) but wondering how many crashes could be avoided (even if they werent the riders fault) if the rider didnt conceed that it was going to happen.

[sinfull]

nice vid ! I want one now (the duc that is, happy with my deisel lol)

[avgas]

hahaha oh man i missed alot in this thread.
Koba - your going down the right path. Its the feel that will tell you the answer.
Ixion is also correct, the machines of today are more complex are require complex math behind them (which is why i recommenced that some reading was required).
I recently read however that its not the fact that devices are more complex now - its just that they are visual more complex than previous attempts. Its an interesting argument when you think about it - an interesting example i found was when i was doing my pre-apprentice stuff for panelbeating. I made a sill for an Austin A35 panelvan. This was super complicated as it involved 2 cones meeting a cylinder. My classmates took 1/4 of the time to make a sill for a 1984 Corolla hatch.
Another example would be to map heat transfer in cast non-pure iron of the old days and compare it to the heat transfer of the new titanium. So have the designs become more complicated or the science behind them? An interesting argument.
But basically to cut the science out if is quite simple. Braking like all mechanical things relies on the man machine interface. Or how i like to put it - The moron that pushes the buttons. Not even ABS can save a moron.

[dipshit]

at what point do you decide it is inevitable?


In that last 1 to 1.5 seconds.

Although it has never come to that for me, it is another skill for staying alive. Why should someone just sit there and go through the handlebars and A-pillars of a car? No thanks. But hey, you can if you want.

[scracha]

2 second gap, 4 in the wet.???

Hmm... I always wonder why we need to double the gap in the wet??
Surely the vehicle in front of you and behind you are also influenced by the the wet road and will take a longer time to come to a stop, so wont the gap between vehicles be unchanged??


Cos decelleration (braking) isn't linear. By the time you react you're doing 100 whilst the car in front is maybe doing 80. At this point you're maybe 1 second behind them. Try checking out the braking distance from 100 compared to 80 and then go figure.

On a typical bike with just a 2 second gap in the dry you're gonna end up hitting them....but at least you won't hit hem as hard as the @#$cktards who leave pretty much no gap.

[Drew]

It's well and truely obvious when shit looks inevitable. Most of the time you know as soon as the emergency appears wether you'll stop or not.

[scracha]

It's well and truely obvious when shit looks inevitable. Most of the time you know as soon as the emergency appears wether you'll stop or not.

Umm....not always. I've managed to brake, slide and wiggle through gaps that I thought I had no chance of achieving on the many occasions some stupid dog/pedestrian/car/bus/lorry (I've hit all 5!) pulls out in front off me. Even when I've not managed to totally avoid, the bike's have ripped off bumpers and glanced off cars with much less severity than I would have had I just "given up".

Rubber on tyres ALWAYS slows you down quicker than your body sliding along the road........so as long as it's upright, STAY ON THE BIKE AS LONG AS POSSIBLE*. If the bike's going down then launch yourself away from the @#$cker.


*unless you're a silly bunny who's got no brakes and there's some nice kitty litter next to you.

[dipshit]

Umm....not always. I've managed to brake, slide and wiggle through gaps that I thought I had no chance of achieving on the many occasions some stupid dog/pedestrian/car/bus/lorry (I've hit all 5!) pulls out in front off me.

Well good for you. However many motorcyclists do end up using their bodies to reshape cars. If they had presence of mind to stand up on their foot pegs in that last second before impact, then maybe they may have got away with only broken legs instead of much much more severe injuries or death.

A mate of mine once saw a guy on a Harley take off from a set of lights only to run smack into a red light runner. The rider stood up just at the last moment and did a complete somersault over the car and landed on his feet... then promptly walked over to the car driver and started punching him in the head through his open window. He said it was the most coolest thing he had ever seen!

[CHOPPA]

Well good for you. However many motorcyclists do end up using their bodies to reshape cars. If they had presence of mind to stand up on their foot pegs in that last second before impact, then maybe they may have got away with only broken legs instead of much much more severe injuries or death.

A mate of mine once saw a guy on a Harley take off from a set of lights only to run smack into a red light runner. The rider stood up just at the last moment and did a complete somersault over the car and landed on his feet... then promptly walked over to the car driver and started punching him in the head through his open window. He said it was the most coolest thing he had ever seen!

hahaha yeah id have liked to see that! well maybe the second half! Good point about standing up i guess? i had never thought about that, gotta be scary though

[dipshit]

Good point about standing up i guess? i had never thought about that, gotta be scary though

Nowhere near as scary as the alternative though.

Watch what happens to a bike on impact. The rear end usually kicks up as the front plows in and the bike comes to a rapid stop. If you are standing up with your legs locked, (even if you are still hanging on to the handlebars leaning forward) then that energy will send you flying like an injection seat.


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[moT]

All you guys sound like a bunch of old women bikkering

[scracha]

another tip...unless yuou well schooled at slamming down the gears blipping the throttle etc and using the engine to brake aswell...just pull the clutch in at the start of the emergency braking!! saves you having to slow the inertia of the engine aswell...and theres a lot of weight spinning around in a small engine!
Disagree totally on this.

[scracha]

Well good for you.

No need to get sarky.



However many motorcyclists do end up using their bodies to reshape cars. If they had presence of mind to stand up on their foot pegs in that last second
If you'd read my post and noticed the bit about
If the bike's going down then launch yourself away from the @#$cker. then you'd see we're basically saying the same thing.

LOTS of accident happen because inexperienced motorcyclists "give up" on braking and/or cornering, panic and then do stupid things.

[henry]

All you guys sound like a bunch of old women bikkering

Welcome to the internet.

[Deano]

It's well and truely obvious when shit looks inevitable. Most of the time you know as soon as the emergency appears wether you'll stop or not.

And a little voice in your head says "I don't want to be here !!!!"

[Biggles2000]

This might answer some of the questions,but might change in the wet.
http://youtube.com/watch?v=ZZKRphfVHqI

Hell I want one, the car that is.....

[Chrislost]

Good point about standing up i guess? i had never thought about that, gotta be scary though

how could you ride on the road and watch cars pulling out and not try and think of somthign to do other then smack into them?
a) other side of the road
b) footpath
c)over the top + get insurance

[Naki Rat]

This YouTube clip came up out of another thread and makes a lot more valid points than that with the Lambo'.


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[The Pastor]

Bro bikes can easily outbrake cars, easily.

[quickbuck]

Good video Naki Rat.
Says it all, and is VERY Fair.

All of you who think your bike can out brake a car.... Well, put it this way:

NO BLOODY WONDER WE KEEP CRASHING!!!!!!!

[EJK]

Well that's a high tech street-sports Skyline GT-R. I wonder if Buell could out brake a Corolla.

[Deano]

....once its crooked and it tucks, you are screwed.


Maybe if you slam the brakes on as hard as possible and it flicks out instantaneously, but on the track (and road a couple of times) with progressive but hard braking, I have had the front start to tuck, ease of the brake a tad and it comes back into line.

Edit - oh, this is braking into a corner so might be a slightly different scenario.

[RT527]

True dat.

Amazing how many motorcyclists have NO imagination.

Sorry I disagree they all imagine they are Valentino Rossi......With the reactions and skill to boot.

[quickbuck]

Well that's a high tech street-sports Skyline GT-R. I wonder if Buell could out brake a Corolla.

Oh FFS!
The reality is the Skyline will not actually brake "that" much better than the Corolla....
Just like an 09 Gixxr 1000 will not brake "that" much better than an 82 GS1000.

There will be metres in it.
The truth is there is more than just a few metres between a car and a bike when it comes to ability to stop!

It all comes down to physics.... friction/ transfer of energies etc.... etc....
Remember there is a huge contact area of rubber on the road in a car.. Alas your bike doesn't have this....

[Deano]

Sorry I disagree they all imagine they are Valentino Rossi......With the reactions and skill to boot.

Everyone needs a dream to aspire to. lol

[cowpoos]

Bro bikes can easily outbrake cars, easily.
not a shit show...go back to school kid!

[Deano]

Just like an 09 Gixxr 1000 will not brake "that" much better than an 82 GS1000.



That woiuld depend a lot on the GS having 'near new' (good condition) brakes though eh ?

I rode an 86 Gixxer 1100 a few years back and the brakes were absolute crap. I couldn't believe how quick White Trash was on it over the Taka's, maybe that's why, cause he had f all brakes to slow him down LOL

[Indiana_Jones]

2m is all a bike needs!

-Indy

[The Stranger]

Bro bikes can easily outbrake cars, easily.

Fuck this is just the best time of year for fishing isn't it?
Even with shit bait like this you are still getting decent bites.

[bane]

Well that's a high tech street-sports Skyline GT-R. I wonder if Buell could out brake a Corolla.

test i quoted in a thread about the vmax:

emergency stop from 100kph:
2009 CBR600rr (with ABS) = ~41.7m
2007 Mazda 3 GSX hatch = ~32m

(also saw another test with a CBR1000rr - no abs = ~39m)

GT-R from memory was just over 30m

[EJK]

Oh ok...</10char>

[2wheeldrifter]

Bro bikes can easily outbrake cars, easily.


Maybe your bike vs a FJ holden... could be close:scooter:

[The Pastor]

Fuck this is just the best time of year for fishing isn't it?
Even with shit bait like this you are still getting decent bites.
wtf u on bro, if the bikes got usd not only can it outbrake any car, but you can over take it within 1 lap of taupo short. dont ya kno

[ManDownUnder]

Bro bikes can easily outbrake cars, easily.

Yup - and the more travel in the forks the better it is.

I understand it allows a progressive compression of the entire suspension train to make sure the front wheel's contact patch is kept even, pushing the tread smoothly into the substrate maximising braking efforts (or more correctly reducing the chance of slippage... aka skidding).

[NDORFN]

I'd like to see a car that can outbreak the bike I ride. I thought all sports bikes inherently had far better braking than cars. Guess not.

[Jantar]

Some bikes can outbrake some cars, and some cars can outbrake some bikes. It all depends on the tyres, brakes, speed at which the test is taken at and what result you want.

[BMWST?]

i think a bike might outbrake a car at lower speeds,where the mass has less effect,dont forget kinetic energy is related to the SQUARE of the speed.I think the ducati vs car would have been closer if the track was dry.It wasnt just damp it was soaking in some parts

[Deano]

Some bikes can outbrake some cars, and some cars can outbrake some bikes. It all depends on the tyres, brakes, speed at which the test is taken at and what result you want.

And the skills of the driver/rider.

[The Stranger]

wtf u on bro, if the bikes got usd not only can it outbrake any car, but you can over take it within 1 lap of taupo short. dont ya kno

Fuck off, stop talking smack man, you know you're never going to be as good as skidmark.

[Flip]

You are dreaming. Cars out brake bikes every time, and bikes corner slower.

Ducati vs a Lotus 7 (40 year old design car)
http://www.youtube.com/watch?v=Qfy1VO4ePlA

[Devil]

The only thing an R500 has in common with a Lotus 7 is it has 4 wheels and they're roughly in the same place. Otherwise there is NOTHING in common.
I'd expect just about any of the caterhams to spank a bike round a track unless it had big straights.

[cowpoos]

I'd like to see a car that can outbreak the bike I ride.

Your Naive....

[Richi]

a bike would stop way quicker if ur doing a stoppie :scooter:

[Kickaha]

a bike would stop way quicker if ur doing a stoppie :scooter:

Dream on...

[scumdog]

I've found they're neck and neck when hitting an oncoming logging truck..

[JohnC]

Friction,,,the thing that stops you,,,is dependant on two things.
Wheight, and surface texture of both the road and the tyre.
Cars have more of both.
Surface area plays no part,,,transport industry tests show that 1 tonne sitting on a very small surface has exactly the same break lose point as the same wheight spread over a larger area.
A simple test is to take a smooth board,place a steel block of a known wheight on one end and tip it until the block moves.
Then take another block of the same wheight but larger surface area and do the same thing.
You will find both blocks move at the same level of tilt.
So the amount of wheels you have doesn't increase your breaking potentual.
It's all about how good your tyres are and how much wheight you can put onto them.
The fact that so many bike riders drive straight up the arse of cars is also a pretty good indercator of cars out breaking bikes,,,,as well as showing lots of bikers are nowhere near as good as they think they are.:bleh:

[cowpoos]

Friction,,,the thing that stops you,,,is dependant on two things.
Wheight, and surface texture of both the road and the tyre.
Cars have more of both.
Surface area plays no part,,,transport industry tests show that 1 tonne sitting on a very small surface has exactly the same break lose point as the same wheight spread over a larger area.
A simple test is to take a smooth board,place a steel block of a known wheight on one end and tip it until the block moves.
Then take another block of the same wheight but larger surface area and do the same thing.
You will find both blocks move at the same level of tilt.
So the amount of wheels you have doesn't increase your breaking potentual.
It's all about how good your tyres are and how much wheight you can put onto them.
The fact that so many bike riders drive straight up the arse of cars is also a pretty good indercator of cars out breaking bikes,,,,as well as showing lots of bikers are nowhere near as good as they think they are.:bleh:

nice theory...but your one is gravity induced...

We are slowing movement with friction...like different sized brakes [more pad area etc]...

[gatch]

Surface area plays no part

Without even looking further into it I don't believe this for a second. You would have people believe the a motorbike would brake in the same distance if it was running 30mm pushbike tire as opposed to 120mm motorbike tire ?

[NDORFN]

Your Naive....

Your grammar sucks.

[Thunder 8]

Without even looking further into it I don't believe this for a second. You would have people believe the a motorbike would brake in the same distance if it was running 30mm pushbike tire as opposed to 120mm motorbike tire ?
Youre onto it..More tyres more surface contact area, MORE friction ,faster stopping.The bit of steel analogys got fuck all to do with rubber on the road.Perfect conditions etc when braking full on hardly exist,try out breaking a car in an emergency stop at speed...........prepare for hospital.

[cowpoos]

Your grammar sucks.
http://en.wikipedia.org/wiki/Na%C3%AFve <--- there you go idiot.

[Dare]

http://en.wikipedia.org/wiki/Na%C3%AFve <--- there you go idiot.

Think he was referring to your/you're. Hahaha, not spelling.

Pretty sure 4 wheels and all that weight = more friction & better braking. And the side-side turning time with that ducati made a good point. Never really thought of bikes as being less agile than cars but there it is.

Makes me wonder what the braking properties of one of these would be!
Looks almost as fun as a bike...

[steve_t]

Your grammar sucks.

You're stealing Hitcher's job :laugh:

[mossy1200]

applied traction force against weight to determine distance to stop.
Bike equals less contact patch .. negative
Bike also equals less weight to stop...positive
Bike tyre equals softer compound...positive
Slipery surface will move advantage towards larger contact patch.
Reaction time is the killer.
Rider watching what is happening beyond the car stands a lot better chance.
If you let the car knock off 20kph before you start to brake then you give away all the advantage and the distance has allready decreased before you start braking.
Skill of rider is factor

Conclusion .RIDE LIKE YOU LIKE LIVING.:shit:

[lankyman]

Not a hope in hell.... less weight pinning it down and a bike has about 4 inches total tread on the gorund maximum at any time a car has 4x 8-10 inches.

Also less weight means less kinetic energy to be reduced...remembering that most bikes weigh about 1/6 of what your average car does.
I have always been under the impression that on a track a car is quicker through the corners, and the bike will make up the difference through being able to accelerate/decelerate a hell of a lot quicker (due to it's huge power:weight advantage)

Example:
Yamaha R1 weighs 270kg (with rider) and has 180hp
A car weighing 1400kg and will need 933hp to acheive same power:weight ratio

[Dare]

The bike will make up the difference through being able to accelerate/decelerate a hell of a lot quicker (due to it's huge power:weight advantage)

Example:
Yamaha R1 weighs 270kg (with rider) and has 180hp
A car weighing 1400kg and will need 933hp to acheive same power:weight ratio

The difference is a bike needs a short wheelbase to achieve quick turns and as such is liable to flip over forwards/backwards. This is why some cruisers can stop faster than sport bikes and why drag bikes are so long.

Against that skyline the Ducati seemed slightly heavy due to the large engine, I think a light 600/750 could have held it in corners/braking and still edged ahead in a straight line... Just an impression though.

[bane]

I have always been under the impression that on a track a car is quicker through the corners, and the bike will make up the difference through being able to accelerate/decelerate a hell of a lot quicker (due to it's huge power:weight advantage)


Well, we now know that even a humble Mazda 3 can easily outbrake a CBR1000rr with a semi-pro rider (by ~7m at 100kph). Also, even I can achieve that stopping distance time after time in the car - but unlikely I would have the skill to get the best stopping distance out of the bike...

The issue the bike has on the track is that because it is so much faster in a straight line, it has a lot more speed to wipe off to get through the corner (especially as it lacks the mechanical grip to carry the same speed through the corner as the car). Therefore rider has to be on the brakes much earlier than the car (and for example, GT-R ends up having to avoid taking the Ducati out at the corner entry)

[jono035]

I noticed a few people mentioning friction vs contact area. Strictly speaking friction doesn't change with contact area, but that is only for 2 non-deformable surfaces.

Tires deform as they come into contact with the road and loss of traction is either due to the tire tread buckling out of the way (tread shuffle) or the rubber itself not having enough shear-strength and giving way under load. In both of these cases more contact is better, although as per usual there are a heap of other factors as well...

[cowpoos]

I noticed a few people mentioning friction vs contact area. Strictly speaking friction doesn't change with contact area, but that is only for 2 non-deformable surfaces.

Errrrr do explain???

[jono035]

Errrrr do explain???

http://en.wikipedia.org/wiki/Friction

For the basic model of friction of 2 solid, dry surfaces in contact, the friction doesn't change with contact area, only with the material's coefficient of friction and the force pushing the 2 objects together.

Basically says a 1kg weight on a single block of wood will be just as easy to pull along concrete as a 1kg weight on 2 or more blocks of wood. This gets quoted a lot when talking about tires, but it doesn't apply in this case because it misses out a lot of real world factors, especially the shear-strength of the rubber involved and the fact that the tread moves sideways when comparing it to the rim while cornering.

[jono035]

Although apparently the version of 'basic friction' which I had always discounted as being too simple to be more than a rough indicator is a couple of years out of date anyway... From the Wikipedia reference:

# CORRECTED: FRICTION IS NOT CAUSED BY SURFACE ROUGHNESS

Some books point to surface roughness as the explanation of sliding friction. Surface roughness merely makes the moving surfaces bounce up and down as they move, and any energy lost in pushing the surfaces apart is regained when they fall together again. Friction is mostly caused by chemical bonding between the moving surfaces; it is caused by stickiness. Even scientists once believed this misconception, and they explained friction as being caused by "interlocking asperites", the "asperites" being microscopic bumps on surfaces. But the modern sciences of surfaces, of abrasion, and of lubrication explain sliding friction in terms of chemical bonding and "stick & slip" processes. The subject is still full of unknowns, and new discoveries await those who make surface science their profession

When thinking about friction, don't think about grains of sand on sandpaper. Instead think about sticky adhesive tape being dragged along a surface.

[rocketman1]

The one thing I have to say only once is:
Practice stopping
Practice Stopping
PRACTICE STOPPING

EVERY ONE CAN GO FAST, NOT MANY CAN REALLY STOP FAST

[Jantar]

Here we go again. Some very interesting scientific test results for motorcycles at: http://www.msf-usa.org/imsc/proceedi...ngDistance.pdf

Have a look at the table on page 6.

Now for cars, have a look at http://www.movit.de/rahmen/stoptbl.htm

Notice that most bikes do stop quicker than most cars, but that there are many cars that can stop shorter than the best bikes.

[Biggles08]

Just riding behind a van on a tight back road coming down a hill, the van driver braked very heavily for a road off to the right, he couldnt turn right because of a car coming the other way that he had to give way to.
I only just managed to stop, ie the road was so narrow I could get by, I would have ended up in the ditch.
It got me thinking, my bike is new, older bikes probably dont have such good brakes, how would they got on in the same situation.
The question is can a motorbike out brake a new car with ABS etc
Ques. Do I have stay more than 10 car lengths behind a van/car at say 100kmh , can I safely stop in time?
It gave quite a fright actually, as I wasnt expecting such a quick stop,I was lucky to have my hand already with 2 fingers on the brake.
You live and learn another lesson aye

Not a chance! If you had the best of both vehicles the car would out brake a bike every time.....pure physics. For the same reason (well not exactly the same but similar one) a car can corner much quicker that a bike could ever dream to...unless of course your skidmark riding a magic ZXR250 / 400.:Punk:

[Pixie]

:yawn:

Is it true a bike can keep you drier than any car?

[The Pastor]

its a tricky one with race tracks as the bikes will be having a much higher entry speed (due to the acceleration) to the braking zone, so (if all other factors are the same) would have to brake earlier.

but cars can easily hold more corner speed than bikes, easily.

[Mikkel]

It all comes down to physics.... friction/ transfer of energies etc.... etc....
Remember there is a huge contact area of rubber on the road in a car.. Alas your bike doesn't have this....

The contact area has nothing to do with the amount of available friction. The secret is contained in statement "4 contact points versus 2 contact points for the bike". With 4 contact points there is both longitudinal and lateral stability - with two there is no lateral stability.


i think a bike might outbrake a car at lower speeds,where the mass has less effect,dont forget kinetic energy is related to the SQUARE of the speed.I think the ducati vs car would have been closer if the track was dry.It wasnt just damp it was soaking in some parts

Well, if the speeds are the same - surely the parabolic relationship is irrelevant. As for weight - you available friction increases linearly with mass - as does the intertia, the kinetic energy and the momentum. When braking the mass cancels out - at least in the first approximation - when you start to consider induced torque due to mass distribution relative to the contact points (which is what gives you stoppies and wheelies btw) then it starts to matter.


Friction,,,the thing that stops you,,,is dependant on two things.
Wheight, and surface texture of both the road and the tyre.
Cars have more of both.
Surface area plays no part,,,transport industry tests show that 1 tonne sitting on a very small surface has exactly the same break lose point as the same wheight spread over a larger area.
A simple test is to take a smooth board,place a steel block of a known wheight on one end and tip it until the block moves.
Then take another block of the same wheight but larger surface area and do the same thing.
You will find both blocks move at the same level of tilt.
So the amount of wheels you have doesn't increase your breaking potentual.
It's all about how good your tyres are and how much wheight you can put onto them.
The fact that so many bike riders drive straight up the arse of cars is also a pretty good indercator of cars out breaking bikes,,,,as well as showing lots of bikers are nowhere near as good as they think they are.:bleh:

Indeed, it's worthwhile pointing out that while weight equals more friction it also equals higher inertia - and in the same proportion.
The only ways to provide higher friction without increasing inertia are: 1) Optimised tyre compounds and 2) Downforce!
Downforce is not really viable for bikes since their aerodynamics suck - the Skyline on the other hand most definitely has got a great deal of downforce (I think it comes with a splitter and spoiler as standard equipment).


nice theory...but your one is gravity induced...

We are slowing movement with friction...like different sized brakes [more pad area etc]...

It doesn't matter - friction is friction and ultimately braking friction on bikes is limited by how much force your front wheel can manage to put into the road. And that force depends upon gravity.
If you can break hard enough to do a stoppie then it isn't your brake system that is limiting your braking potential anymore.


Youre onto it..More tyres more surface contact area, MORE friction ,faster stopping.

It is obvious you have no idea what you are talking about.



Bikes loosing out to cars ultimately comes down to two points:

1. Aerodynamics - they have them, we don't.
2. Lateral stability - means a car can change direction faster than the bike since they don't have to shift weight and tilt the bike over before commiting to the next corner.

[Flip]

Cars do not do stoppies because they have a much lower centre of gravity. Most performance cars also use aerodynamic trickery to generate down force which adds greatly to braking at higher speeds.

[Thunder 8]

It is obvious you have no idea what you are talking about.



Not obvious at all ,you have no idea what i know.

[imdying]

Not obvious at all ,you have no idea what i know.You talk more bullshit than Batman. I'll take more contact area etc over youre bullshit any time.:finger:Wouldn't more contact area give you less grip as there is less force per square inch pushing the tyre into the road?

[Mikkel]

Not obvious at all ,you have no idea what i know.You talk more bullshit than Batman. I'll take more contact area etc over youre bullshit any time.:finger:

As I said, it is obvious you haven't got the first clue what you are talking about. There's really no need to provide additional evidence.


Wouldn't more contact area give you less grip as there is less force per square inch pushing the tyre into the road?

Indeed, that's the whole thing - while the area might grow larger the pressure (force per area) just drops. Depending upon what you are trying to achieve the end result is pretty much the same - the force is constant irregardless of contact area. There are some situations where a larger area is better than a small area - and the opposite is also true.

Let's take snow as an example - if you are driving (or riding if you are brave) on deep snow you want to have a large area so you can stay on top. If it is a thin layer on top of a firm surface, you want to have a small area so you can cut through to the good stuff underneath. Same goes for mud... which is why landrovers (good off-roaders) have tall skinny tyres.

[Thunder 8]

As I said, it is obvious you haven't got the first clue what you are talking about. There's really no need to provide additional evidence.



Indeed, that's the whole thing - while the area might grow larger the pressure (force per area) just drops. Depending upon what you are trying to achieve the end result is pretty much the same - the force is constant irregardless of contact area. There are some situations where a larger area is better than a small area - and the opposite is also true.

Let's take snow as an example - if you are driving (or riding if you are brave) on deep snow you want to have a large area so you can stay on top. If it is a thin layer on top of a firm surface, you want to have a small area so you can cut through to the good stuff underneath. Same goes for mud... which is why landrovers (good off-roaders) have tall skinny tyres.

yep ok then.