Braking

[jrandom]

Sure, I'll take a day off work and see you there on Friday 16 May.

Excellent news!

We're not going to let you back out now, you know.

[McJim]

Back when I were a lad, most trackdays, with the exception of a "school" that Tony McMurdo ran were just bike setup and practice days for "proper" racers, and they didn't like us non-racers getting in the way. They felt themselves considerate if they gave us a decent learn and taught to stay out of the way of people who could ride. They also did not share information with lesser mortals.
:

It's amazing how people with some ability or other look down on those that don't - I remember moving to a different town in Scotland when I was about 16 and being invited to go roller skating...which I had never done before...I was terrible and got bullied on the floor by better skaters. I don't know why they surmised that because I couldn't skate this somehow translated into being unable to kick the shit out of the bastards afterwards which I promptly did. They seemed surprise that someone who couldn't skate could kick their heads in.

Nearly fucked up some skinny little runts at a kiwitrack day last year at Pukekohe too but thought better of it.

[jrandom]

*giggle*

[Trudes]

That's getting close to the mental image I got, eh McJim sk8er boy!!

[James Deuce]

Ahh crap. Avril Lavigne ruined.

[McJim]

Och! Ah'm awa' in the huff.....grrrrrr

[xwhatsit]

Absolutely untrue and I'll find the Performance Bikes article that demolished this myth once and for all.

They used bikes from Valkyries to Blackbird's, with and without ABS, and they absolutely demolished a small hatch with ABS, traction control, and yaw control in terms of braking distance. Even the Valkyrie, and even in the wet. The more experienced testers were beating the ABS equipped bikes by metres.

There have been a couple of significant studies carried out in the UK using accelerometers on race bikes, and John Reynolds, multiple BSB champ was using almost exactly the same amount of braking force, wet & dry. He just took longer to apply that maximum force in the wet.

Well, I see what you're saying and it might very well be true, but like JRandom and co., you're a little bit abstracted from the real world. There's a significant proportion of us riding around (especially commuters) on older bikes with crap brakes, like GN250s and GB500s and SRX400s and Superdreams. I don't think they'd be quite as good as a Blackbird or Valkyrie (cruisers supposedly quite good at stopping, long rake and fat tyres).

Secondly, even if you've got the braking horsepower, it requires quite a bit more skill to use it on a bike compared to in a car. Soccer mums can just mash the pedal, lock it up, whatever, and it'll still stop in a reasonable amount of time; but it requires a lot of practice and skill to use all the braking potential of a good bike. I appreciate that that's what you're saying -- learn to use it -- but for most of us (definitely myself) JRandom's advice regarding learning to dodge, rather than stop, is pertinent.

[James Deuce]

Well, I see what you're saying and it might very well be true, but like JRandom and co., you're a little bit abstracted from the real world. There's a significant proportion of us riding around (especially commuters) on older bikes with crap brakes, like GN250s and GB500s and SRX400s and Superdreams. I don't think they'd be quite as good as a Blackbird or Valkyrie (cruisers supposedly quite good at stopping, long rake and fat tyres).

Secondly, even if you've got the braking horsepower, it requires quite a bit more skill to use it on a bike compared to in a car. Soccer mums can just mash the pedal, lock it up, whatever, and it'll still stop in a reasonable amount of time; but it requires a lot of practice and skill to use all the braking potential of a good bike. I appreciate that that's what you're saying -- learn to use it -- but for most of us (definitely myself) JRandom's advice regarding learning to dodge, rather than stop, is pertinent.

Excuses!

Everyone sees Supercars being tested against Superbikes and the Ceramic/Carbon brakes absolutely thrashing the radial calipers and steel disks of a Superbike. That's abstracted from the real world.

Skill? You're already more skilled at handling a motorcycle than most people ever will be in a car. You shouldn't be learning to dodge or brake, you should be building a suite of skills that match the situation you find yourself in.

[xwhatsit]

I'm not against the learn-to-brake thing you're talking about. I think it's an excellent idea. I just thought I'd point out that for most commuters, what you said is not quite true just yet. Wait until you can pick up old GSR600s for $2000 on Trademe for commuting in a decade or so.

[Ocean1]

There's a significant proportion of us riding around (especially commuters) on older bikes with crap brakes, like GN250s and GB500s and SRX400s and Superdreams.

This interests me. The only bike I've spent much time on that positively couldn't lock the front wheel on dry tarmac was a BSA bushman. Everything else managed, with more or less lever pressure, to achieve something aproaching maximum braking potential of the front tyre.

In fact I believe some of the drum braked bikes delivered better fedback/feel than most of the later disk brake set-ups. Some faded, true, but in a one-off emergency brake they still pushed the limits of the tyres traction.

So, if your bike can't actually lock the front wheel with a reasonably desperate grab I'd probably get it fixed so it can. If so then discussions about braking "power", while relevent for some performance criteria, don't mean much when it comes to a single emergency event. Learn to use the brake up to the tyre's full potential.

Or else.

[Motu]

They used bikes from Valkyries to Blackbird's, with and without ABS, and they absolutely demolished a small hatch with ABS, traction control, and yaw control in terms of braking distance. Even the Valkyrie, and even in the wet. The more experienced testers were beating the ABS equipped bikes by metres.

As someone who does brake testing with a meter a dozen times a day - I often have trouble getting an ABS equipped car to get a pass reading,often several attempts to get 51%.Worse in the wet.The only advantage is heavy braking in a corner - an ABS car will actually stop very well full hard on the brakes in a wet corner....without ABS it'd be spinning down the road and down the bank.I've never ridden an ABS bike to know anything about them,but the corner test would be interesting....

[xwhatsit]

This interests me. The only bike I've spent much time on that positively couldn't lock the front wheel on dry tarmac was a BSA bushman. Everything else managed, with more or less lever pressure, to achieve something aproaching maximum braking potential of the front tyre.

In fact I believe some of the drum braked bikes delivered better fedback/feel than most of the later disk brake set-ups. Some faded, true, but in a one-off emergency brake they still pushed the limits of the tyres traction.

So, if your bike can't actually lock the front wheel with a reasonably desperate grab I'd probably get it fixed so it can. If so then discussions about braking "power", while relevent for some performance criteria, don't mean much when it comes to a single emergency event. Learn to use the brake up to the tyre's full potential.

Or else.

I can lock the front wheel, of course, if I just slam it on straight away like a ham-fisted fool with a hairy man-hand. That gives me carpal tunnel, though. But squeezing it on how you're supposed to, no, you won't be locking it. Caliper is shiny-clean and full of fresh pad-meat and rubber bits, about 6 months ago I think.

As for the drum brakes, hell fucking yes. I want SR400 TLS front-end on my RS. I never, ever want to play with hydraulics again for a start.

[Ixion]

This interests me. The only bike I've spent much time on that positively couldn't lock the front wheel on dry tarmac was a BSA bushman. Everything else managed, with more or less lever pressure, to achieve something aproaching maximum braking potential of the front tyre.

The Bushman was fairly late. But none of the Bantams would lock the front wheel on a good surface from any sort of speed.

Same for most of the early 4 5 and 6 inch SLS front brakes. Some of the later 7 inch could maybe manage it from lowish speeds.

A bike that gained a reputation for the front wheel locking up would not have sold, the front brake was universally distrusted.

EDIT: The TLS 8inch drums on late model bikes were far better brakes for non-racing use than the early Jap disc brakes.

[bell]

Anyway, as Jen was saying a few posts/pages back...

The Technique.

1) keep eyes UP on the horizon
2) keep bike upright & controlled
3) close the throttle
4) Apply FRONT brake progressively - squeeze
5) clutch in
6) Apply the rear brake progressively (to about half way, then forget about it)
7) Continue to focus & apply the front brake progressively until bike is completely stationary
8) down change through the gears just before coming to a holt (tap tap tap tap.. no throttle revs!)
9) stop in first gear, left foot down..
10) check mirrors & be ready to escape from possible dangers

The clutch is an important part of the process...

I also recall the instructors teaching that another key reason to pull the clutch in when doing an emergency stop is this:

unless you've been tapping down through the gears you're likely to drop the bike when the rear suddenly locks as the bike stalls. You'll need to have your dancin' shoes on to get a foot out to stop the rather sudden weight transfer that's going to take place.

IIRC one of the RRRS people suggested that the stall speed of the bike was effectively higher than normal (ie. if you're still in 4th when you reach 11km/hr as opposed to being in 1st at 11km/hr)

That made complete sense in my head 60 seconds ago.

Completely irrelevant but important nonetheless: what time does the MotoGP start this weekend someone/anyone? Sky's website is utter shite and I've wasted 20 minutes trying to find out. TIA

[Mikkel]

It's really not like that any more, you know.

I don't suppose there's any chance you'll make it up to Taupo on the Zed one of these days for a play on the track with us young 'uns, is there...

That echoes my experiences trackside as well. The racers I've seen trackside have been happy to talk bullshit and bikes. And no worries about sharing the track either (you get used to being passed at high speeds very quickly when you're riding your ZXR250 together with Robbie Bugden ).

It's amazing how people with some ability or other look down on those that don't

Well, I haven't had that from competent riders in my own age bracket. I have however had older experienced riders point out to me that I was doing stupid stuff without going into any detail - big fucking help, thank you!
Considering I stayed on my bike I can not possibly have done EVERYTHING wrong...

This interests me. The only bike I've spent much time on that positively couldn't lock the front wheel on dry tarmac was a BSA bushman. Everything else managed, with more or less lever pressure, to achieve something aproaching maximum braking potential of the front tyre.

In fact I believe some of the drum braked bikes delivered better fedback/feel than most of the later disk brake set-ups. Some faded, true, but in a one-off emergency brake they still pushed the limits of the tyres traction.

So, if your bike can't actually lock the front wheel with a reasonably desperate grab I'd probably get it fixed so it can. If so then discussions about braking "power", while relevent for some performance criteria, don't mean much when it comes to a single emergency event. Learn to use the brake up to the tyre's full potential.

Or else.

Hmmm, well it's not hard to lock up your front tyre if you don't allow the forward weight-transfer to take place. (Been there, done that - bought the new leathers...)

Depending upon your tyre compound, temperature can be critical.

Some tyres will have enough grip that on a dry road you'll make a somersault before they loose grip if you brake progressively...