Hard braking?

[nathanwhite]

I got to wondering the other day, after I braked so hard my front started to lose traction (not telling why :shifty: and yes, I know its a rubbish tyre) how exactly does one brake?

Now to be clear, I don't mean what control to move, and I know all about progressive braking.

However while progressively braking, would it be better to Linearly increase (http://zonalandeducation.com/mstm/physics/mechanics/forces/directProportion/graph/directAB_html_605bb50f.png), Exponentially increase (http://www.physionet.org/tutorials/epn/image/fig412.gif) or Incrementally increase (http://www.mathatube.com/images/step_graph.jp) the brake force? Over my vast and varied riding career I have been exposed to all three of these at some point.


or does it really not matter as long as you can smoothly transfer weight to the front wheel?

[tigertim20]

you brake depending on the conditions. also pay attention to how you hold the lever, using two fingers gives you less squeezing power than using three, or four fingers, which can be a factor of varying importance depending on the bike, quality of its brake components, tyres, road surface weather and ambient temperature.

I Imagine that everyone has used all of those types of braking depending on the situation.
Im of the opinion that you should take your bike somewhere quiet and safe and practice emergency stops from a variety of speeds, to learn what your bikes, and your personal abilities are when it comes to braking.

its situational.

as long as you brake safely given the circumstances, it doesnt matter how you stop as long as you keep it upright and dont hit anything.

[p.dath]

There is not one anser that is correct. It depends on a lot on the bike. Does the bike have ABS, integrated brakes, linked brakes, disc brakes, drum brakes, a short wheel base, a long wheel base, etc.

You need to try it for yourself on the bike concerned, measure the results, and then figure out what is best.

[FJRider]

Heavy braking is best practiced on a borrowed bike. (thats what friends are for)

[bogan]

Heaps untill you are about to exceed you known 'safe' braking force (which will be less in the wet), then much more care for slowing applied increase in force after that.

I'm assuming you're planning on doing this in controlled circumstances? An oh shit moment is not the best time to exceed your braking limits.

[DEATH_INC.]

I'll stick my neck out and say an exponential increase is the most effective. It's just the initial loading that is usually the problem, once there is load through the tyre you should be able to haul on it pretty hard up to the point of slide/stoppie dependent on the bike/tyre/surface combo.

[Gremlin]

As has been said, the best way to brake depends on the bike and it's features. I'd recommend anyone, either new to riding, or when getting a new bike, to take it somewhere quiet and practise emergency braking. Knowing how the bike responds (like how much weight shifts around and how it affects the bike) could save your life.

As a general approach, you want to brake as hard as possible to slow as quickly as possible, without exceeding the tyres' limits. The limit is reached through a combination of turning, leaning and braking and only has so much to give. If you're using a lot on leaning then you have less to use on braking. The skill is knowing how much you have for each purpose.

[jrandom]

'kin ell folks, you can't teach someone how to brake properly with words on the internet.

Go do some trackdays, nathanwhite.

[nathanwhite]

I sense some practice time coming up . . . :woohoo:

I have another question. If braking reduces fork compliance, and leaning the bike reduces available sticktion, is it theoretically possible to brake that much later into a corner, and release AS you are turning in, rather then release and then turn in?




Go do some trackdays, nathanwhite.

I plan to. However until then, I have the internet and the specifically general advice that I'm getting :niceone:

[p.dath]

I have another question. If braking reduces fork compliance, and leaning the bike reduces available sticktion, is it theoretically possible to brake that much later into a corner, and release AS you are turning in, rather then release and then turn in?

It's theorecticlally possible to have an off, but doesn't mean you should try.

You really want the bike settled for a corner, not unloading the suspension during the corner (and the front fork would still be recovering in this case).

[nathanwhite]

It's theorecticlally possible to have an off, but doesn't mean you should try.

You really want the bike settled for a corner, not unloading the suspension during the corner (and the front fork would still be recovering in this case).

I knew there was a reason I hadn't tried it.

[jrandom]

I have another question. If braking reduces fork compliance, and leaning the bike reduces available sticktion, is it theoretically possible to brake that much later into a corner, and release AS you are turning in, rather then release and then turn in?

Once you get the hang of it, you'll be able to brake pretty hard with your knee already down. Turning and braking at the same time is an essential skill.

But don't just go out and try to do it now, or you'll fall off.

Trackdays trackdays...

:niceone:

(You've had the good sense to get a Scorpio, so you're already halfway to enlightenment.)

[nathanwhite]

Once you get the hang of it, you'll be able to brake pretty hard with your knee already down. Turning and braking at the same time is an essential skill.

But don't just go out and try to do it now, or you'll fall off.


Funny story actually, coming down Auckland's Scenic Drive, in the dark, by myself, came into a corner too hot.......

[jrandom]

Funny story actually, coming down Auckland's Scenic Drive, in the dark, by myself, came into a corner too hot.......

Well, there ya go.

(Did you fall off?)

[nathanwhite]

Well, there ya go.

(Did you fall off?)

yes. :cry:

[jrandom]

yes. :cry:

1. Metzeler Lasertecs. Right now. It's worth borrowing money to get them. Those stock Scorpio tyres will kill ya.

2. Trackdays!

3. Nek minnit, not falling off.

[nathanwhite]

1. Metzeler Lasertecs. Right now. It's worth borrowing money to get them. Those stock Scorpio tyres will kill ya.

2. Trackdays!

3. Nek minnit, not falling off.

1. Yes I agree. However I have already borrowed money to get my suit and good tyres will go onto the bucket project first. Also I am not riding nearly as squiddey as I was then.

2. See above about the bucket.

3. That's the idea!

[Mom]

1. Yes I agree. However I have already borrowed money to get my suit and good tyres will go onto the bucket project first. Also I am not riding nearly as squiddey as I was then.

2. See above about the bucket.

3. That's the idea!

Dont forget the rear brake for stability, makes a huge difference :yes:

[nathanwhite]

Dont forget the rear brake for stability, makes a huge difference :yes:

rear brake? I wuz gonna throw that away. Too much added weight doncha know

[sinfull]

There is also the thought of your suspension being too soft where as it will bottom out, which in turn could make the front slide out when ya hit said bottom !
Good suspenders is damn important which unfortunately alot of folk forget about, good rubber is important but suspension is equal if not a higher priority to sort !

Jr is correct that the scorp is a great lil commute, but could be damn dangerous if ya try and get all squidly on em in stock form !
He's also correct about being able to turn in under brakes, but not before the suspension is under control, or you'll be diving into a left hand corner when ya touch the brakes and leaping out into oncoming traffic when ya release (or is that the other way around ? mehhhh)

some light reading (http://www.gostar-racing.com/information/motorcycle_suspension_set-up.htm)

[george formby]

rear brake? I wuz gonna throw that away. Too much added weight doncha know

I would keep it, damn handy things.

If I don't use the back brake on my bike I reckon my stopping distance is increased by about 20%. Yup, I've measured it:facepalm:
I was inspired to start practicing braking technique a few months ago, it's become a habit & my ability has improved a lot.
For years I rode covering the front brake, an old habit from trail riding but it was pointed out to me that you can squish your fingers if your brakes are soft & it's easy to keep the throttle slightly open when braking, increasing your stopping distance. I proved this myself.:facepalm: Four fingers on the brake now, better feel & better stopping. Another fault I have is not keeping my head up, look where you want to go, not at the bit of tarmac just in front, makes a big difference controlling the bike when the front dives & steering properly. Using both brakes my whole bike squats rather than putting all the weight onto my soft skinny forks.
Ultimately it's about how quick you can stop or evade a hazard, how you achieve it depends on your bike, properly adjusted controls & practicing the right techniques in varying conditions. With practice I can now feel & hear when the front is close to lock up. The tire leaves rubber on the road but does not lock. I've adjusted my rear brake lever to give me more feel & avoid lock ups too.
Same applies to braking in corners, both brakes smoothly applied but with the added interest of having to steer the bike when it wants to turn in on itself. It's a bit arse puckering to begin with but feels fine with practice.
I did'nt read the linear etc stuff, I don't think it's that complicated.

[Flip]

The problem modulating breaking as you enter corners is most normal bikes have a lot of caster, which means the point the tyre touches the road is behind the centre line of the steering head bearings, this has little to nothing to do with fork angle. Caster makes bikes stable, it also causes the bike to stand up and go straight ahead under breaking.

Relatively easy to do on a light weight, unstable race bike. Hard to get right on a heavy stable tourer. Farking hard to get right on my ultra heavy weight Roadking.

IMHO there is an enormous diference between cheap tyres, performance tyres and track tyres. I did a track day recently and was being chased by a car that had half the power to weight ratio of mine, because he had semi-slicks he kept up and I could not get away from him. I had performance road tyres 200hp and 800kg he had track tyres 160hp and 1400kg, at the end of the front straight I was doing at least 40 kph faster than him but he was always right behind me by the time I was 7/8 the way through the infield, he just didnt have the power to pass.

I used to have a GB500TT that had Yokohama Semi-slicks on it. It used to be a hoot to chase sports bikes over the Rimataka hill with only 40hp and a lot of ground clearance.

[jrandom]

I did a track day recently and was being chased by a car that had half the power to weight ratio of mine, because he could drive heaps better than me I couldn't get away.

Trackdays are like that aye.

[p.dath]

IMHO there is an enormous diference between cheap tyres, performance tyres and track tyres. I did a track day recently and was being chased by a car that had half the power to weight ratio of mine, because he had semi-slicks he kept up and I could not get away from him. I had performance road tyres 200hp and 800kg he had track tyres 160hp and 1400kg, at the end of the front straight I was doing at least 40 kph faster than him but he was always right behind me by the time I was 7/8 the way through the infield, he just didnt have the power to pass....

Any chance he was just a really good driver? :)

[Flip]

He was a very good driver, his car was set up as a track car, mine is a fast road car.

[tigertim20]

I'll stick my neck out and say an exponential increase is the most effective. It's just the initial loading that is usually the problem, once there is load through the tyre you should be able to haul on it pretty hard up to the point of slide/stoppie dependent on the bike/tyre/surface combo.
Some of the rider training places point out that with exponential increase, you initially load up the front, which flattens out the frot tyre, increasing its grip area, which affords you the ability to brake harder, safely, rather than just jamming the cunts on. There are other factors as well of course that play a factor.

I sense some practice time coming up . . . :woohoo:

I have another question. If braking reduces fork compliance, and leaning the bike reduces available sticktion, is it theoretically possible to brake that much later into a corner, and release AS you are turning in, rather then release and then turn in?




I plan to. However until then, I have the internet and the specifically general advice that I'm getting :niceone:

yes you can, but it isnt necessarily going to be stable, what you are suggesting means that the front end would undergo a fair bit of extending travel, at the point you are just tipping the bike in,. Ideally I guess you want the bike flat and smooth through a corner

[skinman]

I have noticed that the way to get a good corner is not to unsettle the bike.
If you are braking late, if you release the brake just before turnin the front will rise (unsettling the bike) then be forced down by the corner (again unsettling the bike) whereas if you only fully release the brakes as you turn in & introduce corner load the front will not rise & fall meaning the corner will be smooth.
I have only had this happen due to going in to a corner faster that I would like & trying to lose speed, it seemed to happen & I got round.
Of cause on the road it is much better to have slowed for the corner earlier.
If I remember correctly something is said about this in Twist Of The Wrist as that is racing orientated.

[Ender EnZed]

However while progressively braking, would it be better to Linearly increase (http://zonalandeducation.com/mstm/physics/mechanics/forces/directProportion/graph/directAB_html_605bb50f.png), Exponentially increase (http://www.physionet.org/tutorials/epn/image/fig412.gif) or Incrementally increase (http://www.mathatube.com/images/step_graph.jp) the brake force? Over my vast and varied riding career I have been exposed to all three of these at some point.

I'd say incremental to start with (because there's no point braking a little when yoiu want to stop) then exponential up to as far as you're confident isn't going to lock the wheel, then linear until you stop/lock.


or does it really not matter as long as you can smoothly transfer weight to the front wheel?

Having a few goes for yourself will count for a lot more than all the advicce on the internet.


rear brake? I wuz gonna throw that away. Too much added weight doncha know

On a Scorpio I'm sure it could be quite the giggle on a gravel or very wet road.


I used to have a GB500TT that had Yokohama Semi-slicks on it. It used to be a hoot to chase sports bikes over the Rimataka hill with only 40hp and a lot of ground clearance.

It still is with 40hp a lot of ground clearance and E09s (http://www.ityre.com/i/tyre/2114.jpg).

[pritch]

On a Scorpio I'm sure it could be quite the giggle on a gravel or very wet road.



I think he meant the bucket?

One thing I don't thiink anybody mentioned; if the front wheel locks, let go the pressure on the brake lever.

For those who espouse four finger braking, when you get some decent brakes, good luck with that. :whistle:

[george formby]

I think he meant the bucket?

One thing I don't thiink anybody mentioned; if the front wheel locks, let go the pressure on the brake lever.

For those who espouse four finger braking, when you get some decent brakes, good luck with that. :whistle:

That's a bit like saying you should only use a finger & thumb to control the throttle of a powerful bike.

[pritch]

That's a bit like saying you should only use a finger & thumb to control the throttle of a powerful bike.

Two fingers and a thumb actually :innocent:

And if you can do that at the same time as you operate the brake that's better yet.

[george formby]

Two fingers and a thumb actually :innocent:

And if you can do that at the same time as you operate the brake that's better yet.

Fair call, I still, er, do the same thing when it's warranted, releasing the brake in the corner as I wind the throttle on. Can't do that without sharing my digits around.