Braking In Corners

[REDRIDER]

I was recently ask a question, how do you apply heavy braking at high speed in a steep lean angle? My answer was you don't. Is this correct? I would think that you would have to start picking the bike up.

[wacko]

what i usually do is ease off the throttle and tap on my rear brakes...

cause if i tap my front brake, my bike will automatic straighten up..

i wonder if this is the correct technique..

[rhema83]

I was recently ask a question, how do you apply heavy braking at high speed in a steep lean angle? My answer was you don't. Is this correct? I would think that you would have to start picking the bike up.

You are right. You don't. Brake before you reach max lean.

[jrock7896]

I was recently ask a question, how do you apply heavy braking at high speed in a steep lean angle? My answer was you don't. Is this correct? I would think that you would have to start picking the bike up.

You are right. You don't. Brake before you reach max lean.

 

Well you obviously cant apply brakes very hard at maximum lean angle. If you say “maximum lean angle” then that means you are using up all of your available traction on carrying the speed through the corner. Lets take a more realistic look at braking in corners… Yes you can use your brakes in corners and in fact if you look at any advanced rider you will see that they use their brakes in corners. The technique used is “trail braking” It is called this because the brake is slowly trailed off as the bike slows down for the slowest and most leaned point of a turn the apex. Riders use trail braking for many obvious reasons….

• If you do all of your braking before the turn then you haven’t entered the turn as fast as you could have, if you were to continue slowing right up until apex.

• Braking in a straight line does not give you the same braking distance as a curved line does.

• Being on the brakes and turning in changes the geometry of the bike so that you can turn in a bit quicker.

 

Lets assume you know all this and that you weren’t talking about trail braking at all and that you simply want to know if you can brake leaned over in a turn hauling ass.…

 

YES you can apply brakes at any time on the track. Just remember that anytime you apply the brake, lean the bike, accelerate you are taking up traction and if you at anytime take up more than the available traction you will slid the tire out and most likely low side. So if you are leaned deep and are hauling ass and start to apply heavy braking you can do so up until the time your available traction runs out…. What point will your traction run out???? This is the question and threshold that professional racers ponder, flirt with and experiment with every time they are riding hard.

 

However most professionals I have talked with say that you can get away with much more aggressive braking than one might imagine while leaned deep and that there is some physics formula out there that backs up their claim. I recently went to a school where they covered the formula, I will try and dig up my notes and will post. Essentially though, it tells us that the relationship between braking and lean angle is not directly proportional.

 

Oh yes and the bike does start to want to pick up when braking, but you should be able to counter steer to negate this side effect of braking. THis is obviously done while trailbraking...

 

Keith or anyone please correct me if I am wrong as I am just regurgitating lessons I learned in racing class. this forum is an awesome learning opportunity.

[racer]

Hey REDRIDER and everybody else,

 

 

I'll start with a quote of REDRIDER's original question. Please forgive me for not using the quote function button to better highlight the quotes thoughout this post. I'm techinically forum challenged.

 

 

 

"I was recently ask a question, how do you apply heavy braking at high speed in a steep lean angle? My answer was you don't. Is this correct? I would think that you would have to start picking the bike up."

 

 

You are correct, in a nutshell, you don't. And, yes again, you need to start picking up the bike first before applying "heavy braking".

 

 

I cannot think of a normal riding situation where one would want to apply "heavy braking" while leaned over.

 

In any braking situation, the limits of braking are tied to available traction which will be determined by stresses at the contact patch. Leaning over reduces the size of the contact patch. While riding "at high speed while leaned over", the front tire is already going to be near the maximum limits of traction due to the cornering forces applied to the now smaller contact patch.

 

Reducing the stress on the contact patch and increasing available traction is accomplished by standing the bike up to reduce the cornering forces and create a larger contact patch to which you can now add more stress (braking force). The more you stand it up, the more brakes you can apply.

 

While "dragging" the rear brake might be better than using the front brake in this extreme situation, remember that ANY deceleration will add more weight and stress to the front tire. Just rolling off the gas will increase the stress on the front contact patch.

 

It is possible to be leaned over at a some speed and not be at the absolute limts of traction. And, in an emergency, to be able to use some degree of braking while leaned over. Generally, the braking action itself will cause the bike to start to stand up at which point a rider can gradually increase braking effort.

 

 

As for what the "pro's" do with the rear brake, or "trail braking" into a corner, neither of these relates to the conditions of REDRIDER's question. However, I do want to clarify a couple points with regard to jrock's post.

 

First, trail braking is generally the last part of a "late braking" pass or an attempt to prevent such a pass by another rider. It is NOT the best way to get through a corner fast. In fact, by trail braking into a turn you lose potential entry speed due to the LIMITED traction available because of the BRAKING stress being applied to the tire already.

 

The late braking pass technique is also referred to as a BLOCK pass just for the reason that the passing rider tends to PARK the bike in front of the passed rider who must roll off the gas to avoid crashing into the other rider or choose another line if available. Late braking is also used to outbrake or prevent another rider from passing under braking. Sometimes evenly matched racers will engage in braking duels, especially near the end of a race.

 

Trail braking can also be a survival reaction when a rider perceives their entry speed as being too fast. However, dragging the brakes into the apex frequently creates more trouble with the extra stress on the tire while leaning in. Often a rider who feels a bit too fast at entry is better off flicking it in and adding more gas. But I will let the guru handle that subject.

 

 

 

"• If you do all of your braking before the turn then you haven’t entered the turn as fast as you could have, if you were to continue slowing right up until apex."

 

 

I disagree with this statement. If you finish your braking before the turn you will have more traction leftover to use for speed. You will also be able to flick the bike faster as there will be less weight on the front wheel. Also, being on the brakes compresses and binds the forks preventing the suspension from doing its job of keeping the tire in contact with a bumpy road.

 

 

 

"• Braking in a straight line does not give you the same braking distance as a curved line does."

 

 

I am not clear on the meaning of that statement. Relative braking distances will be MUCH shorter in a straight line than in a corner, again, because there is much more avaiable traction from a larger contact patch and zero cornering forces allowing much stronger braking.

 

 

 

"• Being on the brakes and turning in changes the geometry of the bike so that you can turn in a bit quicker."

 

 

The compressed forks will create a steeper steering head angle and less axle trail in the geometry making the front less stable. HOWEVER, the braking forces will make the front of the bike and the steering effectively HEAVIER and SLOWER. And, again, there is less traction available due to the extra braking stresses at the contact patch. Besides, just being off the gas will create some fork compression and "quicken" the steering geometry with lots more traction leftover for speed.

 

 

 

"... most professionals I have talked with say that you can get away with much more aggressive braking than one might imagine while leaned deep and that there is some physics formula out there that backs up their claim. I recently went to a school where they covered the formula, I will try and dig up my notes and will post. Essentially though, it tells us that the relationship between braking and lean angle is not directly proportional."

 

 

I believe whatever "professionals" made this claim were very much mistaken. I think that the relationship between braking and lean angle is very much DIRECTLY PROPORTIONAL. Please post the 'formula' from your notes. I'd really like to see it. Can you remember the name of the school that "covered" it?

 

 

 

Happy riding everybody!

[racer]

There is much more infromation regarding these subjects contained in the Twist of the Wrist books.

[jrock7896]

Racer....

Thank you for providing your feedback and for disputing my admitted regurgitation of what I learned from others. I have not been riding long and I am not going to pretend I know alot but, I am here to share ideas and thoughts and learn....

Let me ask you this.... If trailbraking is not the fastest way around a track why do I see every single mtogp rider trail brake into corners? Why do most schools teach trailbraking as an advanced technique to get around the track faster?

[racer]

Hey jrock,

 

The simple answer to your first question is that you don't see every single motogp rider trailbrake into corners under normal circumstances. It might be difficult to see that from a TV screen.

 

I've only attended or worked for a handful of riding or racing schools but I can tell you that, in twenty years of riding or racing, none of the schools I have seen taught that trailbraking was an advanced technique to get around the track faster.

 

It might be that trailbraking is discussed as part of the passing or pass prevention technique I mentioned in my previous post, but, that is a very specific situation and is about getting in front of another rider, not about being fast. A rider who charges into corners or engages in braking duels will post slower laptimes.

 

 

R

[jrock7896]

Hey jrock,

 

The simple answer to your first question is that you don't see every single motogp rider trailbrake into corners under normal circumstances. It might be difficult to see that from a TV screen.

 

I've only attended or worked for a handful of riding or racing schools but I can tell you that, in twenty years of riding or racing, none of the schools I have seen taught that trailbraking was an advanced technique to get around the track faster.

 

It might be that trailbraking is discussed as part of the passing or pass prevention technique I mentioned in my previous post, but, that is a very specific situation and is about getting in front of another rider, not about being fast. A rider who charges into corners or engages in braking duels will post slower laptimes.

 

 

R

 

I do not thik your post is accurate..... Read some quotes out there of fast races in AMA and motoGP.. almost all of them talk of trailbraking. In fact receltny I read an ardicle where Randy Mamola was giving a F1 drivier a ride around the racetrack on the Ducati two seater GP bike. THe F1 driver said "My god that was insane, I mean we trailbrake in F1, but I cant belive how much these guys trail brake" Mamola wasnt just doing it to be impressive, its a technique he used in racing as well and not just to stuff and block.

[Keith Code]

Trail braking is a highly useful skill to have for the corners and riding situations where it applies. Decreasing radius entry corners are a perfect example of a kind of corner where anyone might want to trail the brake in.

 

I was told by some car guys that Schumaker's team mate a year ago (don't know his name) who was driving pretty well didn't trail brake at all while Schumaker did all the time so apparently even in cars it is an option based on the pilot.

 

It is also easy to see that MotoGP riders often don't get back to the gas until around the apex of the corner. When you consider that it takes time to finish the release of the brake and move your hand into roll on position you see that the is only very, very slight actual braking going on through the first third of the turn.

 

You can also easily see that even the fastest guys make terminal errors with trail braking so from that perspective it is indeed an "advanced technique"

 

I don't have a quarrel with trail braking except that it can become a crutch for riders who don't have a clue on their turn entry speeds and trailing the brake in becomes a crutch to a rider who doesn't have a good sense of speed.

 

The fact is that trailing the brake is something that should be done on every track braking situation, whether the rider is leaned over or not and this is a huge point for riders when they are trying to "go fast".

 

It's huge because they tend to "charge the turns". THat means they wind up with a lot of brake at their turn in point and that just makes it more difficult to judge the entry speed accurately. Up to the point any riders is still having entry speed problems trail braking won't solve their entry speed judgement errors.

 

In many corenring situations in racing you will get passed if you aren't trailing the brake in. In others, if you can run late turn entries and you have good confidence to get the bike turned quickly you can let someone pass you going in and repass them on the exit because your line will let you drive off the corner harder.

 

On the road, trailbraking is a valuable skill for avoiding obstacles like pot holes or rocks or whatever. As pointed out earlier in this thread, lean angle and braking are porportional. The more lean you have the less brake you can use. If you are overconfident with it you will do a Danny Pedrosa and take out your team mate who is tyring to win a world championship...as an example...or crash on the road.

 

The question then is does trailbraking solve the other basics of corenring like choosing a line, good throttle control, visual skills, rider input errors and so on. I say it doesn't. On the the road to improving speed I believe there are points that build a stronger foundation for the rider than learning to trail leaned over.

 

Keith

[jrock7896]

Your response is greatly appreciated Keith.. Thanks

 

It is interesting what you say about trailbraking used to compensate for poor entry speed judgment. THis is for sure why I started trail braking in the first place. At my home track Cali speedway I would constantly haul ass, brake and then turn in... Once turned in I would be thinking to myself "I could have been going much faster when I turned in." Once I started gaining confidence in trail braking I also gained confiednce in being able to carry more entry speed. Having the confidence to be able to use the brakes at turn in and beyond helped me carry much greater corner speeds. I knew if I misjudged and had to much speed I could continue to scrub speed up until apex. I havent been riding for too long and it seems I am still using trail braking to compensate for poor entry speed judgment, but I belive the ability to know that I can trailbrake and with confidence, will no doubt speed up the process of being able to proplery judge correct entry speeds.