Riding Skills Questions

[HAWK]

The forks will go flying up and flip over to the other side.
So what I am saying is if you apply front brakes at ANY time you will have a torque being applied somewhere else. That torque goes makes the forks travel upward. Now if your going in a straight line the energy lifts the rear wheel off the ground.
So if you lean into a turn while the brakes are still applied it is very hard to countersteer into a turn because as the bike wants to turn in the forks are pulling up on the frame which makes it pull towards the outside of the turn.
Now when you let the brakes off that energy of pulling the forks up is gone so it lets the bike continue what it wants to do. And that is lean into the turn.

Actually that torque will cause the fork to bind and movement of the slider and tube to cease if the torque is great enough. The only thing that is going to move the fork up is weight transfer which has nothing to do with the torque and everything to do with the heat in the rotors. Otherwise your statement is correct and is what trailbraking is all about. You get the rear up, the front down and then a very light input will flip this god aweful agressive geometry into the turn. At this point you release the brakes and the bike will fall (incerase lean angle radically) into the apex where you will now start applying power. You've almost got it but as TZ points out braking while already leaned over and braking before leaning over are VERY different things.

[Court Jester]

damn, this is now my most favoretst thread. thanks a million for everyone's input here. i'm sure it will prove to be a huge help

[J Farrell / Speed Tech Motorsp]

Here Garth you ready for this one. I tried explaining what goes through me mind on the track. This is just one turn with a bunch of crap added into it. Wait till I get the rest of the track done. Hope you have time to read this. It might be the longest post ever.

Blackhawk Farms Raceway

Jason Farrell's Version

Bike: 2005 ZX6R
•   Tires: Pirelli Supercorsa Pro
o   Tire Pressure   
   Front 33 psi hot on warmers pre race
   Rear 33 psi hot on warmers pre race
•   Suspension:
o   Front:   
   Race Tech Compression & Rebound Stack
   Race Tech Springs .90kg/mm
   Rider Sag: 30mm
o   Rear:   
   Penske Triple w/500lb rear spring
   Rider Sag: 30mm
•   Gearing:
o   14/42 or 14/43 depending on conditions(stock is 15/43)

Gears in each turn on track

Turn #   Gear Position
1   3rd
2   5th
3   4th
3 Bus stop   3rd
4   3rd
5   4th
6   2nd
6a   3rd
7   2nd or 3rd

(Depending on if I'm by myself or following someone I'm in 3rd by myself because I'm able to carry more cornering speed through turn 7)

Turn 1
After shifting into 6th on the front straight about 100ft before the tower, I'm getting ready for turn one. Now turn 1 goes to the right so I'm going to start moving my body over to the right side of the bike. I get my butt off to the right side slightly. Now prior to backing off I have my foot over the top of the shift pedal, my 2 fingers on each hand over the levers ready for action. My right palm is resting on the throttle while it is still wide open.
I always keep my hands really light on the bars so I'm barely holding on. My bike position is about 5 ft from the left side of the track. My brake marker for turn 1 is that I hold it wide open until the bridge disappears from my vision above me. Stuff starts happening really quick from here.
I lift up my right palm from the throttle and it slams shut from the spring loaded throttle reel. Using two fingers on the brake lever & all 4 on the clutch lever, I pull the clutch lever in half way just enough to release the clutch plates & unload the transmission gears. I click down on the shift lever once and very quickly release the lever since the difference between gearing ratios from 6th to 5th is very close matching engine speed to rear wheel speed isn't anything to worry about until you get down into the lowers gears.
At the same time I'm pulling in the clutch lever I'm pulling the front brake lever pretty hard. I use about 75%-80% of my full braking right away quickly. The last 20%-25% gets applied more as the front suspension travels all the way down. By the time I shift into 4th gear I'm applying 100% of my braking power. Now when I say 100% I mean the rear tire is just starting to get light. You don't want to too make the rear tire come off the road since you will lose engine braking. Engine braking is very crucial at the speeds I run since I'm going in as late as anyone can go period. If I blow it anywhere in this process I will not make the turn, crash, or run really wide & kill my drive. So over braking is no good either.
While braking my body is all the way back in the seat so I have more weight over the rear tire to help in keeping the rear tire on the road for engine braking & so I can brake even later. Using some form of Grip tape or Stomp tank pads helps me stay back in the saddle to keep the weight over the rear. Squeeze the tank with your knees while keeping the ball of your right foot on the right peg and your left foot is just covering the shift pedal and drive the front part of your heel into the footpeg you want to keep the weight down low and on the pegs. Don't be lazy. You basically want to put all your weight on the pegs and on the tank. Try keeping as much weight as you can off the seat & bars.


Now shifting down to 4th from 5th I still bang the clutch out as fast as I can. I shift from 6th to 4th as fast as I can. I mean as fast as I can period. Like bang bang. Then the last from 4th to 3rd I let the clutch out at about half the speed to match engine speed to road speed even though I have a slipper clutch setup very good I'm still easy on that last clutch drop. The rear end feels like it really light like its about to float away. It slowly steps off to the left, I'm talking about 4 inches as I let the clutch out in 3rd gear. I'm still hard on the brakes, I mean as hard as I can be modulating the lever while feeling if the rear tire is getting too light or not light enough.
While letting the clutch out into 3rd gear & braking hard I shift more weight on the right handlebar say about 75% of the force. Since I am done shifting down I take the weight off my heal & slide my foot back so the ball of my foot is on the peg and drive my left knee into the tank. At the same time upper body is starting to move towards the right side of the bike and moving forward. I let the braking force slide my butt up against the tank while I'm bending my elbows in.
My outside knee & elbow touch together & lock onto the tank. Locking the elbow & knee together helps me control & feel the bike. It keeps the rear from stepping out too far since I am holding the bike inline with my knee of which is connected to the peg & elbow of which is connected to the handlebar. (Of which why I don't use steering dampers much) I can let it step out as much as I want to.
My upper body is moving forward & to the right just before I turn in. Now you're probably asking how I know where to turn in. It's through trial & error of knowing what your bike can do & repetition of laps. I ride off of feeling of just knowing when to turn through memory of what I did last laps & what my experience tells me I can do while going this speed.
Where ever my turn point is at that moment the rear tire is still out of line with the front. It is hard to steer the bike while you have the brakes on so bar pressure on the inside is crucial to keeping the tire pointing outward (which helps countersteering of which turns a bike) because being on the brakes makes the steering want to turn toward the inside of the turn while you lean in because the weigh of the frame, engine, rider, etc has motion in which it is going forward. At that time you now are trying to move that weight behind the steering neck in a different direction to follow the front tire's direction. But what you must realize is that when you apply the brakes the forks want rotate in the direction the wheel is going while it is slowing down the wheel.
Now with that forward motion of the forks at play with the brakes still being applied, the steering has no choice but to turn toward the inside of the corner because the weigh of the frame pushes toward the outside of the turn. So if the weight of the bike and the gyroscopic motion of the wheels, crankshaft, & transmission aren't enough to turn the bike now we want to trail brake!
Now with the rear still slightly stepped out and the bike following your predicted line or feeling slightly light it might run wide. At the right time you let the front brakes off at a nice medium pace and the rear tire will have weight on it again. Since the rear tire has more weight on it than before and the weight of the rider/frame/engine/etc has more weight total inline than the front tire & forks direction. The direction of the rear tire will over power the front tires direction and it will make the steering snap back toward the inside a little. This motion sets the bike up for a nice inside direction while if you do it at the right time will put you on the perfect line at the apex.
Now when you get on the throttle you are opening up the butterflies in the throttle bodies allowing the engine to breathe. So instead of the rear tire driving the motor because the clutch basket is trying to drive the crank while the gas is off. With the butterflies closed the piston can't draw any air into the cylinders which is like putting the brakes on the rear tire. When you crack the gas on you allow the pistons to breath air and the crank to spin freely & match the rear tires speed. Which allows the rear wheel to rotate freely without any resistance.

Getting on the gas sooner also changes the pull on chain so it pulls the rear tire. The chain from the engine to the sprocket gets tight. Since the chain is pulling the rear tire hard and the rear sprocket is lower than the front sprocket. The swingarm actually moves in a downward motion (called anti-squat) which since the swingarm can't go down anymore it raises the frame of the bike up which in turn gives you more clearance between any parts on the bike like the engine covers / rearsets and the ground. It also puts more pressure on the rear tire's contact patch thuse giving more traction.
But there is a trade off to that; too much anti squat only causes the suspension in the rear from working at all! The most anti squat you will have is at peak torque in your engine's powerband. If you stop the suspension from soaking up bumps what happens is when you hit a big bump the rear tire will jump the bump instead of soaking it up which in turn causes the rear to spin stepping the rear tire out sideways and if you chop the throttle you lose all antisquat, drive on the rear tire in which it will gain traction which will cause the suspension to squat and throw you off into a wild side because now the tire is stepped out and it hooks up. The suspension squats and the weight goes to the rear causing the energy to load the rear spring & unload the front springs. The only chance you have in saving this nasty situation is to somehow get your weight off towards the inside of the turn trying to keep the bike from flipping to the outside from the energy of the rear spring bouncing back up. When it does bounce back up you need to be on the inside of the bike to help hold it down and you might land on the tank and save it. Otherwise it's a trip to the moon!
So what I'm saying after all that is if you hangoff the bike on the inside in the direction of the turn you going in it will only help in so many ways. Plus you and the bike are 1. You are married to the thing. What you do together will make how quickly you can get around the track.
Look at Ben Spies. His riding style is the reason he is going as fast as he is. Look at how he hangs off the bike in the Canada Corner @ Road America.


I will tell you that this is a huge reason factory riders are faster than privateers. They are in shape and understand how to ride the bike and make it go where they want it to go.
Some people say that you either have the skill or you don't. Sorry but I don't believe in that. That's old adage. I believe you can learn the skill if you just try & apply the correct thinking.
Back to exiting turn 1.
Now when the throttle is cracked on just before the apex and your flying you better be looking up the track at turn 2, NOT the outside of the corner! Because if you look at the outside of the turn you will end up there. If you look up the track you will be very surprised at how the bike holds a line so much better and you can get on the gas more & more & more. You should be progressively opening the throttle faster & faster.
At this time I'm hanging off the bike as far as I can to keep the bike up as much as possible so I have more tire on the road.  While hanging off & accelerating I am feeling that rear tire & the force between my outside knee & elbow against the tank. I am driving my outside foot into the footpeg to get my butt off the seat slightly. It also helps keep my body towards the inside of the turn.
Now if my rear tire does spin up it will be easy to control since I am bracing my body to the tank with my elbow & knee. Plus my butt is about off the seat which gives me suspension in my knees to help counteract any bumps or hollows in the road. That keeps the chassis less upset.
Your gearing should be set up so that your rpms are just redlining right after you straighten out or slightly after the bike stands up completely. At the apex it should be just at peak torque in your powerband to help you drive off the corner with the most amount of torque available.
About Your weight as a rider:
You and the bike are considered 1 weight. You sitting on the bike are a variable if you want to be. You can alter the center of gravity of you and the bike by moving around to make the bike handle better in whatever situation you need. A lighter weight rider has less weight to throw around to make a difference if he needs. Where as a heavier rider can use weight to his advantage to make the bike do what he wants it to do. But also remember that the more you weight the more your bikes handling can get screwed up if you have it in the wrong place. So kind of like the saying the bigger they are the harder they fall!

I will try to simplify the rest of the track when I write about it later. I'm beat tired. Time for bed. I'll try to keep this lap going several turns a week. By the time I finish I will be able to think about publishing it somehow.
The above writing is owned by Jason Farrell of Speed Tech Racing and is not to be reproduced or copied at anytime. Write Jason Farrell for permission to use this information in this thread.  The above writing is a opinion and Jason Farrell is not responsible for mistakes in spelling or anyone using this information for personal or professional use.

All Photos used above were taken by Alan James Berg of Speed Tech Racing. Thanks Alan!

[J Farrell / Speed Tech Motorsp]

Earlier when I was saying that it makes the forks go up I was talking in reference to the forks being on the bench yet. All I'm saying is that at anytime when you apply the brakes the forks want to rotate in the direction of the wheel which in someway rotates the forks up. I forgot to use the word rotates.
That rotation causes the  frame to lift up causing it to run wide. If your following me. It's hard to write this stuff in words but I'm working on it. "Cause you know sometimes words have 2 meanings". Just try to picture what I'm saying.
Trust me I know how this stuff works. I do it, I don't just talk of it. It just putting it in words in everyones elses mind that is the problem.

[tzracer]

Earlier when I was saying that it makes the forks go up I was talking in reference to the forks being on the bench yet. All I'm saying is that at anytime when you apply the brakes the forks want to rotate in the direction of the wheel which in someway rotates the forks up. I forgot to use the word rotates.
That rotation causes the  frame to lift up causing it to run wide. If your following me. It's hard to write this stuff in words but I'm working on it. "Cause you know sometimes words have 2 meanings". Just try to picture what I'm saying.
Trust me I know how this stuff works. I do it, I don't just talk of it. It just putting it in words in everyones elses mind that is the problem.

Jason, you are correct to a point. You are describing conservation of angular momentum. But you are ignoring the opposing torque being applied by gravity. You cannot ignore the rest of the motorcycle. As you brake, the front tire slows, it is losing angular momentum. The torque that slows the front wheel is applied by the brakes. This torque in called an internal torque - our system being the entire motorcycle. If one part of the motorcycle applies a torque (or force) to another part of the motorcycle, this is an internal torque (or internal force). An internal torque cannot change the value of the angular momentum, hence if free to rotate, the entire motorcycle would begin to rotate in the same direction as the front wheel, ie want to stoppie. However our motorcycle is not free to rotate. Gravity is acting downward through the center of mass (CM). This is an external torque, and external torque can change angular momentum (torrque = the tome rate of change of angular momentum or torque = dL/dt). This is what keeps the bike from doing a stoppie. At the braking done while turning, this torque is more than adequate to keep the rear wheel planted while turning. The rotation takes place in a plane perpendicular (normal) to the front axle. This angle is not correct to raise a bike in such a way to run wide. As a matter of fact, enough braking while turning will cause the rear wheel to begin to lose traction and start to swing to the outside of the turn. I have managed to do this when braking through kink type turns. Somewhat disconcerting, but did not cause my bike to want to run wide.

[tzracer]

We are racing motorcycles here. Not pizza cutters. Just saying that it is obvious that the contact patch will move. You couldn't race a motorcycle with pizza cutters otherwise we would have them on our bikes. I have ridden tons of motorcycles & bicycles for that matter. They all work the same.
I have a mountain bike in my shop that I use for expiriments. I ride that thing around the parking lot and the same principals apply. If I hit the brakes on a bicycle while leaning to the left the tire turns into the corner and the steering neck pulls the bike up toward the outside of the turn.

Take your bicycle outside right now and tell me that is not true.
And for fun sake while going 35mph on your bike brake and lean into a turn. I'll bet it runs wide everytime unless you hit some ice or slick spot today.

The reason the pizza cutter example is examined is to try to understand the phenomena. In the case of pizza cutter wheels, the bike won't stand up under braking, wheels with width will. Therefore the (main) cause must be the with of the tires.

Yes it can happen on a bicycle. When you lean, the contact patch moves from the center of the tire. When you brake this causes a torque that causes the wheel to turn in the direction of the turn (as you correctly describe). Now where you go wrong is in the description of what happens next. The torque you are appling through the contact patch (the one that is causing the wheel to turn, this is not the same torque as being applied to the fork by the brakes) is not parallel (or anti-parallel) the the angular momentum of the front wheel. angular momenntum and torque are vectors - they have a value (length - magnitude) and a direction. When a torque is applied not parallel to an angular momentum, it causes the direction of the angular momentum to change, not the magnitude. This is called precession. The net result is that the front wheel wants to stand up, since the front wheel is more or less rigidly connected to the frame, the result is the entire motorcycle stands up.

The standing up is not the result of the motorcycle trying to stoppie (rotate about the front axle - your experiment with the bench vise), but the result of the torque applid to a turning front wheel when the brakes are applied.

Found this last night

Date: Thu, 30 Jul 1998 09:06:13 +0200
From: "Tony Foale" Subject: MC-Chassis Re: Braking under lean

Patrick asked:

<<
. Why
do bikes stand up when the front brake is applied while cornering and why
do some bikes do it so much more than others?
>>

There are many factors involved, as usual, but one to consider is:
When leaning, the tyre contact patch moves to the inside, so when we apply
the brake a torque is generated trying to steer into the corner, this causes
a precessional motion in a direction tending to make the bike standup.
Tyre width and other considerations will affect the degree of this tendency.
Tony Foale

España ( Spain )
http://www.ctv.es/USERS/softtech/motos

I don't disagree with the affect you are descibing, I am disagreeing with your description of the cause.

Also, as I have been stating, if you are braking before initiating the turn, the stand up affect is not noticed because you push the bar as hard as it takes to make the turn. I have never found trail braking and staying on line to be much of a problem unless I have entred the corner too fast.

If you brake after you have begun turning and you are ready for the bike to try to stand up, you can counteract this by more countersteering. If you are not ready, the bike will stand up, then you will turn more, but the bike has already begun to run wide and you will have to turn even more to get back on line.

One reason Eddie Lawson gave for trail braking was to keep the forks compressed so the the bike would not more upwards with the brakes released and then recompress when turning. He would release the brkes as the cornering forces increased keeping the forks at the same compression through the transition from braking load to cornering load. This makes the bike more responsive to your turning input because you do not have the transient period of the forks diving as the cornering forces are applied.

[J Farrell / Speed Tech Motorsp]

Ok all things equal. I can't ignore the fact that there is gravity. You can still overpower gravity though and do stoppies with enough braking force to rotate the forks around the axle.
If you brake while in a turn and the rear tire comes off the ground, could that be because you have too much weight over the front end & towards the outside of the turn?
Point is you can make a bike pretty much anything if you weight it incorrectly or apply brakes or throttle at the wrong times. If you watch stunt riders you can learn a lot on how to make a bike do what you want it to do.
Off the subject, I don't like when racers talk crap about stunters. Stunters are quite talented riders to do what they are doing. Most of them do what they can do because they think outside the box on how to get their bike to do what they want it to do. Racers can learn from them if they just watch how they do things. Just because they trash their bikes and show what you think disrespect to their machines doesn't make them bad people.
That's what they do. They have to crash to learn. Yes there are dumb asses out there doing it on city streets harming others just like roadracers on the street. They ruin it for the guys that do it in controlled environments. We are all pretty much guilty of one time or another breaking the law and possibly putting others at risk by our actions on the street.

[J Farrell / Speed Tech Motorsp]

Well put & described Brian. I understand the same feelings and know how to act or counteract to it. It's just all the specific words to use must be said right as to not confuse peoples minds.
I think a model should be made to describe this action. I'm working on that.
I also believe that explaining how things work and what actually get affected as a result by writing them will help people better understand it. Using specific words that they don't understand yet will just throw them for a loop even more!

Lets keep this thread going with many examples.

[JBraun]

This debate is also why I laugh when people try to tell me that there is a "correct ride height for a 2006 R6 on pirelli tires"

It sounds like Farrell likes to trail brake really deep into corners, and he's fast.
Ed Key appears to be completely out of the brakes before he turns in, and he's also fast.

If those two riders were on the same bike with the same static geometry, think of the difference in rake, trail, and ride height between the two bikes near the apex of the corner, with one rider on the gas and the other just letting off the brakes.

[J Farrell / Speed Tech Motorsp]

I have been know to wear front tires out just as much as the rear at certain tracks! I like using the front tire to all of its traction at times. I can sometimes have really good days where I will use the front tire to it's maximum by sliding every so slightly all the way to the apex or until I get on the gas.
Thats why I don't like to use a damper. The damper takes away the feel I need to see if the front tire is sliding. Otherwise the damper keeps the steering straight and you lose the feel as to when it will let go.
I don't ride the front in every turn but probably more than most guys.

[jimmyboost]

Your description of why a bike turns wide is not correct. It is due to the fact that while leaned, your contact patch moves towards the edge of the tire (inner edge in the case of turning). This offsetting of the contact patch it what causes some bikes to stand up when braked while turning (not all bikes do it, even with the same front tire, also this affect really wasn't noticed until bikes got wider front tires). ISTR that Tony Foale covers this in his book (I don't have my copy handy) http://www.tonyfoale.com/Main.htm. If your front wheel were like a pizza cutter, it would not stand up under braking.

     You guys should read some of Foales writings, its pretty good stuff.  Brian knows what he's talking about.  Think about the bike, just as a smiplification, lets say its five big gyroscopes; the front wheel, the forks/triples when you turn them, the engine, the rear wheel, and the whole bike when its turning.  So, youre riding completely upright and you brake.  The bike slows down and assuming you aren't turning at all and everything is inline you shouldnt feel much resistance from the bars.  Now, youre braking and getting ready to go into a right hand turn.  You push the right bar out and pull the left bar in initially to initiate the "fall".  When you do this, the bike begins to lean to the right consequently, the contact patch shifts towards the right side of your tire.  Now, remember youre braking, so the force acting on the tire from the gound is pointed backwards.  Because the contact patch is out of line with the center of your front end now, a moment is created between the ground and tire due to this braking force.  This moment acts to rotate the front end (i.e. wheel, brakes, forks, etc.) clockwise, thereby arresting your "fall" and standing the bike upright.  If you were simply braking, gave the correspnding push and pull on the bars to start the turn in, continue braking but released pressure on the bars, the bike would stand itself up.  But, since you want to make the turn, instead of releasing prssure on the bars, you push harder on the inside bar and pull harder on the outside bar to intiate the fall.  Well before the apex youve begun to arrest your fall by pulling on the inside bar and pushing on the outside bar.  If youre still on the brakes, your effort is reduced here.  If not, its just like turning without brakes from then on out.  Also, there is much more force on the front wheel when you are braking and this by itself makes it harder to turn the wheel.

     The best example I can think of for this is braking on the front straight at talladega.  Lets say that were running the course ccw.  Im using this as an example because when you enter the little chicane youre still braking really hard before you let off the brakes and flip the bike over for the left hander.  The initial right hand portion of the chicane isnt very severe, so you arent turning the bike that much, but think of how much harder it is to make the bike turn the way you want it to there compared to when youre off of the brakes and go back in the left hander.

     +1 to Brian for reading Tony Foale.

[benprobst]

this is my first post on this subject, and seeing that I dont want to ramble on for a page im sure i will not write everything that is flying around in my head. however...............

Something I have learned/been drilled into my head by my dad (an accomplished road racer) is thats trail braking is there for a reason. When I come into a corner my main objective is simply to never allow my suspension to move (of course there will be variances bumps, tire slip, etc...). Its all about load, tires will grip exponentially better if the load on them never changes. I load the front coming into the corner with the brakes, compressing the suspension say 75%, as I enter the corner, i slowly trail my brake away, but as my brakes stop pressing the bike onto the front end, the front tire begins to really eat into the pavement and pushes the wheel into the bike keeping my suspension compressed at the same rate, the next step is to roll the throttle on while still releasing the brake continuing to press the front end into the ground until it is time to pick the bike up while keeping my body low and accelerate out of the corner. if you ever find youself doing nothing, i.e. not braking, or not accelerating you could be going faster. fast guys dont coast! the brake and throttle should act as one control acting in exactly opposite ways, as you roll of the gas you should already be squezing the front brake, then as you slowly release brake pressure you should already have the throttle actuated. I often go through a corner that doesnt requir a ton of countersteer without ever closing the throttle all of the way. it works just like braking straight up and down, you dont jab you front brake from 0% pressure all the way to 75 % pressure when you hit your marker, when I hit my marker i squeze the brake to settle the chassis, once settled I am able to aply as much force as I want to.

take it or leave it, im not as fast as some of the other guys yet, but I am new to this, however my family is not and alot of the knowledge gained over the past 25 years has been transfered to me through years of learning through all different types of mediums, bike, dirtbike, car, and road racer.


so there it is, as I reread the posts im sure I will come back with more info but thats what  have for now, have a nice day and start trail braking