Brake progressively

[Motofool]

"Grabbed a handful of front brake" is a frequent sentence found in the crash section.

What is the meaning of that?
Is braking more progressively any better?

Transferring weight from one tire to the other takes time, simply because the bike has inertia that opposes sudden changes in weight distribution and pitch rotation around the CG.

Hence, the normal force on a contact patch (very important for good grip) can only grow up to the optimum value at certain rate.

Sudden accelerations and decelerations can load the rubber transversely much faster than weight transfer can load it perpendicularly.

Modulate the application of brake and throttle, as slowly as conditions allow.

[alex.s]

well worded and accurate.

even if you dont lose traction from overloading the front tire (which as we know can be caused by either the initial brake grab, or when untuned forks bottom out just after the grab), shifting the weight forward too quickly (getting on the brakes too fast) can also throw the rear wheel up in the air, which we all know is undesirable.

[RedOctober]

Originally Posted by Motofool

"Grabbed a handful of front brake" is a frequent sentence found in the crash section.

What is the meaning of that?
Is braking more progressively any better?

For me, "grabbed a handful" is an SR, a panic reaction (one which I've been guilty of as well).
Progressive braking is the way it should be done: hard initial bite, easing off (which then turns trail braking) so you can regulate your entry speed much better without the bike practically doing a stoppie.

The former is a mistake and latter is the proper form. Now...in some cases these two definitions intersect. Ex: Trying to outbrake someone means you are trying to pass, your opponent starts braking and you don't, getting on brakes harder and later. In this case the end result may be the same as "grabbed a handful" but the intent was different.

[choneofakind]

Originally Posted by RedOctober

Progressive braking is the way it should be done: hard initial bite, easing off (which then turns trail braking) so you can regulate your entry speed much better without the bike practically doing a stoppie.

RedOctober you're right for the track. Hard initial bite and then trailing off as you turn in is good. It quickly and smoothly eats away speed, and keeps the bike stable for turn-in.

For the street though, it's best to not make a hard initial bite. You want to progressively (not slowly, just smoothly and gradually) squeeze the lever. For the track, the emphasis is as high of a speed as you can carry for as long as you can carry it, aka, braking late and getting on the gas asap. On the street however, things are a little less extreme. You want to be at a safe turn-in speed a little early. You should already be off the brakes at turn-in, and you should be braking earlier than necessary. So that means a nice progressive brake squeeze, tapering off before turn in (no trail braking on the streets) and then a smooth turn.

[RedOctober]

Originally Posted by choneofakind

RedOctober you're right for the track. Hard initial bite and then trailing off as you turn in is good. It quickly and smoothly eats away speed, and keeps the bike stable for turn-in.

For the street though, it's best to not make a hard initial bite. You want to progressively (not slowly, just smoothly and gradually) squeeze the lever. For the track, the emphasis is as high of a speed as you can carry for as long as you can carry it, aka, braking late and getting on the gas asap. On the street however, things are a little less extreme. You want to be at a safe turn-in speed a little early. You should already be off the brakes at turn-in, and you should be braking earlier than necessary. So that means a nice progressive brake squeeze, tapering off before turn in (no trail braking on the streets) and then a smooth turn.

Indeed. Last thing you need is someone rearending you.

[Motofool]

Originally Posted by RedOctober

.........Ex: Trying to outbrake someone means you are trying to pass, your opponent starts braking and you don't, getting on brakes harder and later. In this case the end result may be the same as "grabbed a handful" but the intent was different.

The process is quicker for braking harder and later, but if the front tire takes the load, a good transition was made; faster but still modulated.

Braking harder should be more an emergency technique than a regular riding technique (street and track alike).

Copied from http://www.sportrider.com/riding_tip...ing_potential/

"When transitioning to the brakes, a precise grab is important too. The goal is for your initial grab to be strong, but avoid stabbing the brakes — an overwhelming initial grab will upset the chassis and compromise front tire grip, plus your suspension needs to be able to absorb the weight transfer."

Copied from http://forums.superbikeschool.com/in...?showtopic=310

"One of the things I have noticed when I watch students is how erratic their turn entry speeds often are. That comes from the idea they have to charge the corners and brake hard but they can tend to over-brake and foul up their entry and corner speed momentum."

[JeffM]

Originally Posted by choneofakind

For the track, the emphasis is as high of a speed as you can carry for as long as you can carry it, aka, braking late and getting on the gas asap. On the street however, things are a little less extreme. You want to be at a safe turn-in speed a little early. You should already be off the brakes at turn-in, and you should be braking earlier than necessary. So that means a nice progressive brake squeeze, tapering off before turn in (no trail braking on the streets) and then a smooth turn.

I always understood that late braking in a race situation (I do not race) is a gamble and not s.o.p. and that slow in, fast out is the quickist way around a track. Maybe a few track riders/racers can chime in here.

Also, I trail brake a lot on the streets (and twisties). It is very benificial to be able to adjust your speed with brakes all the way to mid corner on the street. What happens if you are off the brakes after turn-in then have a situation where you need to get back on them? I would much rather have the chassis settled under trail braking and add a touch of rear brake to slow things a bit more if needed.

Jeff

[choneofakind]

Good point! I personally just make sure that I'm slowed down more than enough before I enter a turn when I'm on the street so that I have a little more margin of error.

[csmith12]

Late braking is not the same as trailbraking on the track.

Late brake is when you stay on the gas to make a pass on a rider pre-corner entry and most of the time the passing rider will stay on the brake to scrub speed from entry to apex (or close to it). We progressively release the brake to transfer weight off the front (bike returns to a more neutral state of suspension) so when the throttle is engaged it doesn't all go to the rear at once.

On a 250 its REALLY important to carry speed throughout and trailbraking is one of the tools that can help. Because on a 250, slow in equals semi-fast out. The acceleration just isn't there.

In the end, your right. It's a gamble, mess up while trailbraking and your chances of going down are increased or you will loose drive on corner exit while the rider behind you is already into the throttle hot on your arse.

While there are pro's and cons to lightly trailbraking on the street. I personally don't do it. There isn't a real need to, (most of the time) just not going fast enough or with enough lean angle for it to matter. Some of the street racers may disagree though.

[csmith12]

One of the best things you can do is read up on how the yamaha school teaches braking. Google up "100 points of traction".

Link to original page on YouTube.

[JeffM]

on the 100 points of traction.

Jeff

[Apex]

I grabbed a hand full of rear brake once. I don't recommend it. It was a rather awkward position to ride in....

[CC Cowboy]

Originally Posted by Apex

I grabbed a hand full of rear brake once. I don't recommend it. It was a rather awkward position to ride in....

Using your hand to apply the rear brake is not recommended.

[Motofool]

Motorcyclist magazine has just published an article from Keith Code about this subject:

"As with so many other riding fundamentals, that moment of brake application is a learned, technical skill."

http://www.motorcyclistonline.com/fe...on_the_brakes/

[Motofool]

Link to original page on YouTube.

[GearMonkey]

^ was that from wet brakes or because the front wheel was locked and had 0 traction?

[Motofool]

Originally Posted by GearMonkey

^ was that from wet brakes or because the front wheel was locked and had 0 traction?

No steering capability = skidding front tire

Yes, wheel was locked; which is easier to have naturally when traction is reduced due to the mix of rain + oil + dust

[GearMonkey]

Originally Posted by Motofool

No steering capability = skidding front tire

Yes, wheel was locked; which is easier to have naturally when traction is reduced due to the mix of rain + oil + dust

newb question, just trying to get a full understanding of the threats and errors so I don't make the same mistakes. Great info, especially the 100 pts vid!

[Motofool]

Another good article:

http://www.webbikeworld.com/Motorcyc...aking-tips.htm


1. Which brake is the most effective?

The front brake is the most effective, giving between 60 & 80% of the bike's stopping power in hard stops, depending upon surface conditions. This is because most of the weight of the bike and rider transfers forward onto the front wheel when the brakes are applied.

A common example of weight transfer is when you trip on a gutter - your feet stop but momentum keeps the top of you going and you fall flat on your face. The weight transfer that takes place under braking on a motorcycle pushes the front wheel onto the ground and makes it grip very well.

2. Is the front wheel likely to skid if you apply the front brake hard?

No. The front wheel is likely to skid uncontrollably and bring you down only if you jam the front brake on hard. If you apply the front brake in a staged (progressive) process, the front wheel may skid but that skid is normally quite controllable.

3. Is the rear wheel likely to skid if you apply the brakes hard?

With most of the weight being on the front wheel, the rear wheel tends to be light under braking and will therefore lock up and skid very easily.

4. How do you control a rear wheel skid?

Control of a rear wheel skid is easy. Just keep your eyes up to the horizon and look where you WANT to go (not necessarily where you are actually going) and the bike will skid in a controllable manner with a minimum of fishtailing.

Basic and advanced braking techniques are best learnt under controlled conditions rather than when a truck pulls out on you! Your local motorcycle school will run a fun braking exercise session for you and some mates if you care to call the school and arrange it.

5. Is braking a natural skill?

Braking, as with any riding skill, is a learned skill, not a natural one. This means you must practice the correct braking skills enough to make them an instinctive reaction before you can be sure that you will do the right things in an emergency. Overseas research has shown that, because of panic overpowering the rider's conscious reactions, nearly a third of all riders do absolutely nothing in an accident situation: they don't even apply the brakes!

If, however, your high level braking skills are so well learnt that they are instinctive, you will do it right, no matter what the situation. However, this requires you to do a lot of high level braking skill practice, the skills will not come with normal everyday riding.

6. Is there a special braking technique that ensures that a rider will get the best out of a motorcycle's brakes?

Yes. The process is called STAGED BRAKING and it involves the rider applying the motorcycle's brakes in a staged process. This gives the rider predictable, progressive braking.

7. In an emergency do we concentrate on using staged braking on both front and back brakes?

This is a controversial subject. Some experienced riders reckon that, even in an emergency when research has shown that panic tends to decrease your riding skills, they can apply the back brake perfectly with no loss of braking on the front.

Well, research has shown that the average rider can only properly concentrate on the use of one brake in an emergency so, unless you think you're road motorcycling's equivalent of a top motorcycle racer, we would suggest that you concentrate on getting the best out of one brake.

Of the front and rear brake on a motorcycle, the one to concentrate on in an emergency is the front brake because if you get that one wrong, lock it up and don't correct that problem then you're going to crash.

According to the American Motorcycle Safety Foundation, if you try to get the best out of both brakes in an emergency, you will get the best out of neither. The MSF says you can't concentrate FULLY on both brakes at one time. You know your mother's old nag, "You can't concentrate on two things at one time"!

So, to get the best braking, you have to concentrate using either the front or the back brake and, since the front brake gives up to 80% of your braking power and incorrect application is likely to make you fall off, it makes sense to concentrate on the front brake.

The American Motorcycle Safety Foundation teaches their instructors that "in an emergency braking situation you should apply the back brake hard and let the back wheel slide if it wants to. This way you can concentrate on what is happening up front; there's enough to think about in the use of the front brake."

8. So how should I apply the rear brake?

Apply it and forget about it. Let the back wheel skid if necessary. Concentrate on using staged braking to harness the superior power of the front brake to save your life.

9. Is Staged Braking difficult to learn?

Given practice, the skill is not difficult to learn. The best way to learn it is to start off with a four stage application of the front brake. Later you can increase the number of stages to make your braking more and more progressive, if you want to.

10.Can you explain four stage braking in practical terms?

To understand four stage braking, think of a rider coming up to a set of lights. Stage One is the force with which he applies the front brake when he sees the lights turn orange some way ahead, in other words, lightly.

At Stage One, the rider is applying the front brake to the point where the brake is just on and slowing the bike down very, very gently to roll to a stop.

Stage Two is the force the rider would use if he was a bit closer to the lights when they turned orange, and he had to make a normal, smooth stop at the lights. So, Stage Two is the firm pull used to bring the bike to a firm, but quiet stop. The rider applies his front brake to Stage One (friction point) before going on to apply to a steady force at Stage Two.

Stage Three. Our rider has dithered about whether to stop for the orange light before deciding he'd better. By this time, he has to stop quite hard to stop. So he applies the front brake to friction point (Stage One), then onto a firm pull (Stage Two) before applying pressure with a strong pull at Stage Three.

Stage Four. The rider very unwisely decides to run the orange only to find, just before he reaches the lights, that they turn red. In this serious situation the rider needs all the braking he's got. So he applies the front brake to friction point, moves onto the firm pull of Stage Two, then to the strong pull of Stage Three, before giving it all he's got at Stage Four.

11. If you "give it all you've got" on the front brake at Stage Four, won't you get front wheel lockup?

Possibly but by using the staged braking process, by the time the tyre gets to the point of locking up at Stage Four, the weight has transferred forward onto the front wheel and any tendency of the front tyre to lose grip is both easily sensed and controlled, unlike a front wheel skid caused by a tyre locking up when the brake is jammed on hard while weight is moving around on the bike under weight transfer.

With correct use of the Four Stage process, controlling a front wheel skid is simply a matter of keeping the wheel steering straight ahead as you relax pressure on the front brake to allow the wheel to revolve again and regain grip.

12. What will happen if the front wheel locks and I don't relax some pressure?

You'll fall off as the wheel will eventually tuck under and the bike (and you) will fall down.

13. How good can you get at emergency braking?

In emergency stops, expert riders are capable of controlling a front wheel skid by releasing pressure on the front brake just enough to get that wheel turning again without actually letting the brake right off. This requires considerable sensitivity on the brakes and the only way you will gain this sort of sensitivity is to practice.

At the NZMSC higher level Megarider sessions, the way the instructors tell if the pupil has reached a suitable standard is whether they can hear the front tyre chattering as the tyre grips at the point of adhesion during emergency stops.

14. Is a bald tyre a liability when braking?

A treadless tyre will quite adequately handle braking stresses on a perfect road surface. The trouble is that perfect road surfaces are more than rare - they're virtually extinct. Tyre tread acts like a broom, sweeping debris, dirt, gravel and water etc off the road surface in order that the tyre can grip the road.

The tread on a sensibly ridden motorcycle can comfortably handle most foreign matter on a road surface - with the possible exception of oil (especially diesel oil), thick mud, and smooth wet paint. But link a bald tyre with foreign matter on the road surface and throw in braking stresses for good measure, and the crash will resound throughout the neighbourhood.

15. How should I brake on slippery and loose surfaces.

Carefully but not timidly. The secret to good braking on poor surfaces is observation. If you know what's under your wheels you can tailor your braking to the surface.

So, keep an eye on the road surface. If you cross a slippery surface under strong braking the front wheel may lock. This is why riders who brake late and hard for orange or red lights often spill off - into the middle of the intersection. The fall occurs because the rider fails to ease the front brake as the front wheel crosses the white line that crosses the lanes at the edge of the intersection. Then the front wheel breaks loose under braking on the slippery surface, the rider panics and freezes, and he and his bike head groundwards...

The basic requirements for braking on a loose surface such as gravel are the same as those applying to braking on a sealed surface. The difference is that you must observe the requirements more strictly on gravel.

You must brake in plenty of time, preferably brake while upright and in a straight line (any braking while leaned over in gravel is extremely hazardous), use both brakes very progressively, carefully interpret the noise from the front and rear tyre while braking to detect and counteract any wheel lock-up, know your road surface, and take particular care when braking on gradients, inclines, and heavy cambers.

[Toly]

I wonder how much of this is still relevant with everyone going gaga over ABS. In fact, most new riders refuse to buy a bike without them

[Motofool]

Originally Posted by Toly

I wonder how much of this is still relevant with everyone going gaga over ABS. In fact, most new riders refuse to buy a bike without them

The physical principles still apply to bikes equiped with ABS.

The anti-blocking mechanism can only do this (instead of the rider): after it feels that the tire slows down respect to the pavement's relative speed or totally stops (skids), it reduces some of the internal hydraulic pressure of the brake system temporarily (over-ruling the pressure comand coming from the hand/foot) for enough time for the contact patch to regain grip and the tire to regain rotational speed (and steering capability).

It is just a remedy to a sloppy braking (for the specific traction conditions) and it consumes some time and braking distance by doing all those minute evaluations and corrections.

[choneofakind]

^^ yeah, but it makes the bike more stupid-proof for them.

[Motofool]

Originally Posted by choneofakind

^^ yeah, but it makes the bike more stupid-proof for them.

ABS is a great tool, indeed !!!

Just saying that:
1) The rider is still the one deciding when and how the brakes are applied.
2) The friction between discs and pads is the one stopping the bike.
3) There are more or less efficient and safe ways or methods of emergency braking.
4) The physics of motorcycle braking (deceleration) has been and will always be the same.

[AlanDog]

Originally Posted by Toly

I wonder how much of this is still relevant with everyone going gaga over ABS. In fact, most new riders refuse to buy a bike without them

If you watch the Yamaha video above, they talk about gradually loading the tire so the contact patch can squat down. Gradual loading can't be done by ABS, it has to be done by the rider, because the tire isn't locked up, or even close to locking up. Once traction is broken, recovery will be harder--then, ABS may help, but it may be too late...

My housemate has the latest ABS/traction control on his KTM 1190, but that didn't stop him from low-siding on a slick road. It's pretty easy to exceed tire grip in 'bad' situations (or with bad technique). ABS will not keep your head on straight and tell your body how to react to the situation. And with people thinking technology is going to keep them from crashing, maybe that will lead to more crashes? In the case of my roommate, I think it did give him confidence that exceeded his skill level. The actual technology did nothing for him, there just wasn't enough grip.

Think about it. You're balancing on two wheels with your body, and when your bike starts sliding, the computers can't put your body into the right position to recover from the slide. Think about how a bump in the road can decrease the contact patch to almost zero while leaned over in a turn. No amount of ABS or traction control is going to increase the amount of grip available in that situation.

Ken Hill gave a few classroom session at my last trackday, and he talked about braking in terms of going from 1-2-3-4-5 in terms of increasing braking pressure, and then 5-to-1 while decreasing braking, in the context of slowing for a turn. This really helped me for some reason--assigning a number to it instead of just saying "gradually apply the brakes and gradually release the brakes". He emphasized using brake release to modulate turn entry lean-in; trading braking for lean angle.

Anyways, I'm just ranting. I struggle with gradual braking on the zero, although getting 'weaker' no-name organic brake pads has helped me modulate the brakes tremendously.

[Motofool]

Updating post #15:

Link to original page on YouTube.

[alex.s]

[choneofakind]

Yeah, I've seen that footage before and I still don't think it's fair. That's a brake grab to intentionally lock it. They should have done a third run with the rider manually feeling the threshold of lockup rather than just grabbing the **** out of the brake lever.