Emergency Braking

[NDORFN]

rear brake is used more for handling control than braking. ie. can help you pull a tighter line in or smoothe the power delivery on exit

Can you give a little more detail on how that works? Does it pull a tighter line by sliding the rear out? How does it smoothen power delivery on exit?

[p.dath]

It's true assuming your bike isn't an '87 GPX250. Don't worry Sil3ntwar, I've been through it all on my '88. Just practice at a safe speed until you've found the technique and setup that offers the best results. The effects of various theories varies so much from bike to bike (particularly due to age and condition of suspension) that you'll have to practice and learn new habbits when you upgrade anyway.

Actually that was one interesting conclusion the report came to - that the technique for stopping in the shortest distance was not affected by the type of bike. They found you used the same technique no matter what.

[p.dath]

I don't use the rear brake at all, ever. Maybe if I was riding something with a particuarly heavy rear wheel I'd give it a very light tap to kill the momentum, but I'd never use the rear as a form of deceleration. I prefer to devote any momentary thought that's left after spending the majoriy of my attention on front braking and riding position to collision avoidance. That little split second it would take to tell my right foot to help out is a split second that can be spent telling my balls to pitch in and get some more lean on or get ready to make a safe bail.

The report found that using the rear brake as well as the front increased the average de-acceleration from -0.711 g to -0.774 g. So using both brakes makes a difference. They also noticed it only makes a difference at the very beginning of the process.

[p.dath]

IME - You are able to maintain greater control over the bike when using both front and back brakes appropriately rather than just the front (like most I know do). Changing down gear early is also a big help.

Interesting enough they spent an entire day investigating the effect of down shifting during emergency braking. The report found that down shifting as part of emergency braking INCREASED the distance to stop by around 2m.

So you can down shift as you approach something, but forget doing it once the emergency starts happening. Your time is better spent doing other things.

[_STAIN_]

Can you give a little more detail on how that works? Does it pull a tighter line by sliding the rear out? How does it smoothen power delivery on exit?

some thing you just need to try when riding. in a slowish moderately tight corner, you find it tightening up, just apply a little rear brake. the bike will pull a tighter line.
maybe hard to feel the effect on a gpx, but on more powerful bikes we feather the rear brake to control power delivery while leaned over. Once upright release and your gone, technique commonly used in racing. Cheers

[NDORFN]

Actually that was one interesting conclusion the report came to - that the technique for stopping in the shortest distance was not affected by the type of bike. They found you used the same technique no matter what.

Does the phrase "Type of bike" refer only to makes and models, or does it encompass ages and conditions aswell. If you got on an old GPX250 like Sil3ntwars' and put some rear brake on then applied the fronts, everything would get very perpendicular all of a sudden. Don't ask me how the physics work, but I know from experience that they lurch forward no matter which brake you use, taking all the weight off the rear and putting too much on the front. Getting the front brake on first get's the weight foward and the rider prone for adding in some gentle rear brake. It's probably only a factor in bikes with slushy suspension.

[NDORFN]

some thing you just need to try when riding. in a slowish moderately tight corner, you find it tightening up, just apply a little rear brake. the bike will pull a tighter line.
maybe hard to feel the effect on a gpx, but on more powerful bikes we feather the rear brake to control power delivery while leaned over. Once upright release and your gone, technique commonly used in racing. Cheers

I don't actually ride the GPX anymore. I'm in the process of aquiring a ZXR so it's something I'll test out. I can sort of imagine how it'd work. Cheers for the advice.

[p.dath]

Does the phrase "Type of bike" refer only to makes and models, or does it encompass ages and conditions aswell. If you got on an old GPX250 like Sil3ntwars' and put some rear brake on then applied the fronts, everything would get very perpendicular all of a sudden. Don't ask me how the physics work, but I know from experience that they lurch forward no matter which brake you use, taking all the weight off the rear and putting too much on the front. Getting the front brake on first get's the weight foward and the rider prone for adding in some gentle rear brake. It's probably only a factor in bikes with slushy suspension.

They mostly compared sport bikes and cruisers.

I don't have sufficient experience to really answer the question, but they found that the rear brake only had any impact at the very beginning of the exercise. I would think if your getting a "perpendicular" effect you still need the rear brake, but less of it.

[The Stranger:Me]

I have substantialy re-written the section on braking now.

http://www.kiwibiker.co.nz/wiki/Braking

I've broken it into sections, as I came to the conclusion that the reason there is a lot of different answers about braking is because there are a lot of different situations we get into that require an emergency stop.

While I based the article on a comprehensive test report, I think it could now benefit from input from advanced riders (certainly more advanced than me!), and it should also be easier to add sections to cover emergency braking in different scenarios.

The "comprehensive" test is significantly flawed as noted.

Learn to think for yourself.

[mossy1200]

The whole point of rear brake first is that it lowers the bike and the weight transfer enlargens the contact patch of the front tyre.
Personally I use the back brake just before applying the front in wet conditions on the track as a planned approach braking prior to corners as I feel it reduces the chance of losing traction when the front is applied hard.
I release the rear brake after the front has taken effect.
I think that you will find some bikes like cbr1100x and many beemer use linked brakes to lower the bike under brakes and they do stop quite quickly with that method.

[NDORFN]

The whole point of rear brake first is that it lowers the bike and the weight transfer enlargens the contact patch of the front tyre.
Personally I use the back brake just before applying the front in wet conditions on the track as a planned approach braking prior to corners as I feel it reduces the chance of losing traction when the front is applied hard.
I release the rear brake after the front has taken effect.
I think that you will find some bikes like cbr1100x and many beemer use linked brakes to lower the bike under brakes and they do stop quite quickly with that method.

This makes sense.

[Benk]

I wouldn't call it fucking good advice mate, I'd call it fucking buraucratic bullshit. You probably won't find much of that in your Motorcycle OFFroad Code.

Haha, have you tried it? I suggest you do, as you can go much faster, and more stable on gravel. Might save you (or more likely someone else reading this) from falling off one day.

Anyway, Im done. Ive got nothing to prove to some know all on the interweb.

[sinfull]

I'd hate to see a learner, come across an emergency braking scenario and have a flashback from this thread ! The word sideways springs to mind !

But then i guess most learners would go for the rear brake first anyway aye ?

Rear brakes are for wet whites lines or grass in my book ! I generally ride with two fingers hovering over the brake lever, by the time my toes have lifted off the peg and move to the brake pedal, i would have scrubbed 50% off my speed !

If ya want to get into trail braking to have the rear squating in a corner and to help save the wheel from spinning up on the corner exit (talking track here) Well shit i cant help ya, as i aint even that experienced on the track yet (experimented with it, but i got enough to try and think about before that becomes habit)

[NDORFN]

Haha, have you tried it? I suggest you do, as you can go much faster, and more stable on gravel. Might save you (or more likely someone else reading this) from falling off one day.

Anyway, Im done. Ive got nothing to prove to some know all on the interweb.

Of course I haven't tried it. That would involve actually riding a bike and well, that would mean I'd have to leave my computer. No, I just sit here making shit up all day. Look at my profile, I don't even have a bike! Seriously though, why would you want to encourage people to go faster on gravel with thier road bikes? Especially the begginers who are most likely to read this shit.

[p.dath]

The "comprehensive" test is significantly flawed as noted.

Learn to think for yourself.

I guess I disagree with you. But the thing with Wiki's is to quote sources of information that support your point of view, so that a nice factual line is formed.


I think if would be great it you could add a piece to the wiki and also cite a significant study to support your view, so that it becomes a richer document.
Otherwise it is just here-say.