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Old 09-19-2009, 08:41 PM   #1
MOKE1K
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Cool How do you brake?

More geared towards the trackday junkie or racer, but all of this can help, even on the street or atleast thats what I think.


I recently read an article from Keith Code about this technique, straight up braking. Never really realizing that I had learned this style of braking along time ago on the Mountains of Oahu. Long story short we would ride to the top of the mountain road and turn around, turn the bikes off and coast down the road. "No brakes racing" keeping the bike in neutral and staying tucked for every ounce of aero dynamics I could muster out of my 87VFR750. All you had to do was "NOT" use your brakes, and you’d win every time. He who brakes the most,...loses! Its very different without the gyroscopic force of the engine spinning but I learned NOT to trail brake, and just pick the line and set the speed, then turn in.

This takes tremendous trust in your tires and line choice and this article promotes that style and the way I have learned to use the brakes. If you trail a lot-you should switch your styles or at least experience the difference. It gains better traction from both tires and allows you to read the suspension more accurately. Trail braking, when avoidable, allows you to get on the gas earlier in a corner as well, but the line and speed have to match perfectly once you initiate the turn in. Long read, but worth the
knowledge. Good Luck and hope it makes you faster!

By Keith Code:
Braking it turns out, does much more than just slow you down. Fork flex, geometry changes, tire deformation and a host of other forces come into play, drastically affecting the way the motorcycle negotiates a corner. The forward pitch of the bike under braking can steepen the fork angle by as much as 4degrees on a Ducati 1098, for example. This reduces trail by roughly an inch on the same hypothetical 1098, and effectively shortens the wheelbase as well. Front-wheel load can double under heavy braking. Tire height shrinks under load, further decreasing trail by a slight amount. At the same time, however the contact patch both broadens and lengthens rearward, which can restore trail by as much as one inch. Trail is now close to where is started, unless the tire locks up-at which point you'd have very little stability, owing to an instant reduction of trail. Braking doesn’t sound so simple anymore,...does it?

Even the best forks flex under braking. This flex creates "stiction," a term that describes a fork's action becoming sticky from internal friction. That, in combination with heavy spring compression, reduces tire compliance with the road. Finally, frame flex can introduce a negative loading-and-unloading influence as well.

There are two primary methods of braking for a corner: straight up braking, where you complete braking before turn-in, and trail braking, where you stay on the brakes after turning and feather off brake pressure as you near the apex. When trailing the brakes into a corner, still more forces come into play. Additional drag is created on the inside edge of the now/larger contact patch. That drag twist the fork inward, which tends to counter / steer the bike back up out of it's lean.

On a well designed bike with proper geometry, the fork rotates side to side to maintain tracking and stability. Under the above conditions, it is heavily restrained. This promotes an increase and bar-twitch. The tire, stretched in at least three directions, puts enormous and conflicting stresses (and releases) into the fork motion too. All of these factors can contribute to a heavy, sluggish feel at the bars. Under all cornering situations, the tires are slipping. In fact, depending on speed and corner radius, the wheels rotate as much as ten or twenty percent slower than the vehicles velocity, scrubbing off both speed and rubber from the tires. This often-for-gotten fact is called “slip angle,” and adds the tendency to lose traction from the front tire under extreme trail-braking situations.

On the positive side, the steeper fork attitude and shorter wheelbase allow the bike to carve a sharper turn given the same amount of lean angle. Adding to this positive effect is an ever-tightening cornering radius that results from the decreased speed. And don’t forget the rear tire-unloading under heavy braking, it takes less effort to turn. Engine rpm and wheel speed decrease at the same time, reducing qyroscopic effect from the rotating masses of both.

What this all means is that somewhere between initial turn in and final release of the brakes, the bike is able to achieve its tightest turning arc. This can provide a highly skilled rider with subtle control of both his cornering line and corner speed. Straight up braking inspires less physical drama, but still demands intense attention from the rider. In some cases, completing the braking act before you turn is more difficult than trail braking to the apex. In this case the bikes turning arc must be established before the turn is initiated. The ability to predict line, apex and exit is vital. This requires, among other things, superlative visual skills. In addition, quick and accurate steering is a must. The rider must have enormous confidence in front and rear tire grip before flicking the bike into the turn. Coordinating brake release and turn-in steering must be spot on, or the suspension will rebound as the bike is entering the turn. This all requires deft coordination and impeccable timing.
The reward for such precision is a chance for the rider to get on the gas much earlier, letting the suspension settle into its most compliant range of operation. Additionally, he can better maintain and adjust corner speed, release bar pressure earlier (huge!) and with both tires sharing the cornering load, reduce unnecessary lean angle. All of these factors will increase both speed as well as traction and suspension feedback.

The essential difference between trail braking and straight up braking is which control – the throttle or the brake- is used to adjust the riders line. Trailing brakes requires excellent front end feel and is often cited as an advanced technique. Rightfully so- most Motogp crashes occur under deep trail braking circumstances. Even so, when you consider the judgment and coordination demanded to skillfully execute quick and accurate straight-up braking entries,
I’m not convinced trail braking is the more advanced technique. It may be the other way around.
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Old 09-20-2009, 03:32 AM   #2
Dr_Sprocket
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Thanks for sharing, Mokester.

I have never given any serious thought about how I brake. During the MSF's motorcycle safety class, they instruct straight up braking, completing the braking before entering the turn. Thinking about how I brake, I do brake into the curve. I do this sometimes because I carried too much speed into the corner and sometimes intentionally to help change my line.

I think I have always done trail braking, having learned it while riding bicycles. When ripping down a mountain at 45mph on tires no wider than an inch, you learn how to feather the brake and brake in the turns.
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Old 09-20-2009, 05:11 AM   #3
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No problem DR. Sprocket, I use trailing as a way to correct the speed in, if I get it in too hot Iam safe to use it. When racing though its best to try and not use it, mostly so I can get on the gas earlier.
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Old 09-20-2009, 06:43 AM   #4
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Originally Posted by MOKE1K View Post
... its best to try and not use it, mostly so I can get on the gas earlier.
But wasn't the point of the article that you could get around the track faster if you did use trail braking? I think the implication was that nobody could hit every corner with such precision that they wouldn't need to brake in the corner, and that the riders who did, as opposed to choosing a less desirable line, went faster.

Either way it is an excellent write up, as all of the "Code-Breaks" are. MO could add a lot to it's content by featuring a highly technical writer in the manner of Code or even a "how-to" or "Ask the Expert" type of thing.
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Old 09-20-2009, 12:11 PM   #5
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My take on this is that anyone that rides on the street at posted speeds would never need to know how to trail brake and never use it. For spirited riding on the street, you better know trail braking, because you will get into a corner too hot one day, and knowing how to scrub speed without standing the bike up or panicking is essential. Street riders need to learn panic braking way before worrying about this. Chances are someone will cut them off and they need to hit the brakes without locking up and falling down. I think Keith Code has the best stuff out there for advanced riding. Some people think he's a nut.
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Old 09-20-2009, 02:31 PM   #6
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My take on this is that anyone that rides on the street at posted speeds would never need to know how to trail brake...
I... ahem... can neither confirm (cough) or deny that I may... or may not... uhh... ride at speeds above the legal limit.
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Old 09-20-2009, 03:05 PM   #7
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I... ahem... can neither confirm (cough) or deny that I may... or may not... uhh... ride at speeds above the legal limit.
If you rode the speed limit in Fort Lauderdale you would either be shot by a road-raged cager or run over by a semi. The speed limits are absurd; they have no basis in reality.
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Old 09-20-2009, 03:20 PM   #8
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Quote:
Originally Posted by longride View Post
My take on this is that anyone that rides on the street at posted speeds would never need to know how to trail brake and never use it. For spirited riding on the street, you better know trail braking, because you will get into a corner too hot one day, and knowing how to scrub speed without standing the bike up or panicking is essential. Street riders need to learn panic braking way before worrying about this. Chances are someone will cut them off and they need to hit the brakes without locking up and falling down. I think Keith Code has the best stuff out there for advanced riding. Some people think he's a nut.
Since he's one of the most successful trainers of road racers I'll stick with what he says.

I still don't trust modern tires as much as people who didn't grow up with the tires we had in the 60's 70's. As I recall there wasn't this powersliding around. You either stuck to the road or you went down. Not much warning either. I'd credit tires with the improvement in performance more than horsepower.
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Old 09-20-2009, 04:15 PM   #9
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Originally Posted by Kenneth_Moore View Post
MO could add a lot to it's content by featuring a highly technical writer in the manner of Code or even a "how-to" or "Ask the Expert" type of thing.
I nominate MO's resident "expert" on everything from the Economy to Motorcycling to W............

Oh wait - can't have 'im - he's been banninated for being a stupid fcuk.
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Old 09-21-2009, 08:57 AM   #10
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Quote:
Originally Posted by longride View Post
My take on this is that anyone that rides on the street at posted speeds would never need to know how to trail brake and never use it. For spirited riding on the street, you better know trail braking, because you will get into a corner too hot one day, and knowing how to scrub speed without standing the bike up or panicking is essential. Street riders need to learn panic braking way before worrying about this. Chances are someone will cut them off and they need to hit the brakes without locking up and falling down. I think Keith Code has the best stuff out there for advanced riding. Some people think he's a nut.
What about when you have to swerve around someone and your using the brakes. Not trying to start anything but thats trail braking to dont ya think.
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