racer
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Posts posted by racer
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The physics is simple: lean angle is dictated by speed and radius.
Whether it is 50 or 64 or 42 degrees, lean angle will always be the point where the centrifugal or cornering forces are balanced by gravity around a 'moment arm' or common lever defined by using a point between the contact patches as a 'fulcrum' and the center of combined bike/rider mass as the point where gravity (vertical) and lateral g is applied.
Centrifugal or cornering forces are determined by speed combined with "radius" or how tight a corner is. So, the faster you go in a given corner, the higher the cornering forces and the more you have to lean to balance. And/or the tighter the corner for a given speed, the higher the cornering forces and the more you have to lean to balance. There is no single lean angle for a particular speed or vice versa. It will always be speed in conjunction with the radius of a given corner. Whether or not you can carry enough speed in a specific corner to be leaned at 50 degrees will depend on the available traction of your tires and your ability as a rider.
Wiki has a reasonably easy to understand entry on the subject:
http://en.wikipedia.org/wiki/Bicycle_and_motorcycle_dynamics
I find this physics education website very approachable for the layman:
http://www.glenbrook.k12.il.us/gbssci/Phys/Class/BBoard.html
Have fun!
racer
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"lowest overall time by cornering more slowly" say what??? this doesnt make any sense at all. the amount of throttle that can be applied while leaned over is limited (more accurately, the rate at which throttle is applied) but if i am applying the throttle at the same point in the turn (at, just before, or just after the apex depending on the corner) as someone entering slowly how are they going to be faster than me, especially if i have a higher corner speed and we are taking similar lines??
im not doubting the philosophy, im just trying to understand it and im a little slow.
OK, when I say "slow" in, it is a relative expression. I should say, slow enough to be well in control and the bike settled, hence, able to flick it faster which enables you to get back on the gas sooner as opposed to charging in, out of balance, running wide and having to wait while the bike settles before you can get back on the gas.
The amount of throttle applied while leaned over is limited not only by how far you can twist your wrist or the rate at which the throttle can be opened at full lean to acheive 60/40 best balance for best traction, it is also limted by time (how long) on the throttle. How long you can be in the throttle is dictated by how soon you can get back on the gas. And, the fact is, if you are going too fast on the entry, you aren't able to get back on the throttle at the same point in the turn as someone who is a bit slower and able to flick it faster. Also, I think you should always be getting back in the gas before the apex and accelerating through the turn. I can't think of a turn where that isn't true. How do you define "apex"?
racer
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So, one reaches max traction either way, but, won't max traction with the brake applied be at a slower speed as braking reduces available traction one might use to carry more speed?
Whereas by not trailbraking and then rolling on the throttle, one can carry more speed to start with and then add even more speed when rolling on the throttle to shift weight off the front?
but isnt the whole point to maintain the intended line? going faster (higher rate of speed in a specific section of the turn) isnt necessarily the goal if it takes you off of your line *cough bayliss*.
Yes. I'm not sure what you are trying to say here. From my point of view, it is late braking (going faster in a certain section) that takes me off my intended line.
im a total newb, but i cant say for sure when i trail the brakes and when i dont but i know i do it often. in every intentional case (not the "oh ###### tooo fast!! case) i begin releasing the brake just before turn in and trail off as i lean with zero brake pressure by the time my knee hits the ground. that is because as soon as i reach max lean angle im rolling on the gas.OK. Sounds like you are using a good technique for trailbraking. So, the question becomes: when, where and why?
for me TB has two great advantages: i control the rebound effect after hard braking and i can brake a few feet later and scrub off the last bit of speed in the turn while maintaining my line.stu, racer, keith; if this sounds bad please correct me.
Maintaining "your" line. What does that mean? Does that mean maintaining the line that you have chosen because you have decided that it is the best line for that corner? Or does it mean the line that is dictated to you by the fact that you are trailbraking? And how do you define "best line"?
In TOTW II, Keith defines the "best line" for any corner as the one that allows you to get back on the gas the soonest. Do you agree with that? Does the line you use trailbraking fit that definition?
If you read Keith's article posted by 2big above, then my question to you is the same as the last poster: can you control the rebound effect by letting off the brake in a controlled fashion before intiating the turn entry? And, then, being off the brake, isn't it possible to literally flick the bike faster without all that braking stress/load on the front tire? And, hence, carry more speed?
When trailbraking, are you carrying more speed, or simply braking later and actually making things more difficult for yourself (even though you might feel more comfortable or in control with your fingers on the brake) with heaveier steering and what amounts to what must by definition be a slower entry speed to accomodate the braking loads on top of the cornering loads?
What do you think?
racer
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Racer - you're right. I think I mentioned that I tend to over think things.
Really? I can't imagine what that is like...
Part of the problem in my case is that why I intellectually 'get it' translating that in to the kinestic confidence to do the actions is a stumbling block.to save some time (and writing) - we are talking about something that needs to be done and experienced. We can post (and will) on message boards all day about this stuff, but at the end of the day it has to be done. You have to actually experience this stuff. But talking about it is fun.
Ah, indeed. "Naming is not knowing" as my Zen-Buddhist guru used to tell me during my years as a callow youth at the monastery.
One may open a technical manual and memorize all the words and study all the pictures and talk all about re-building an engine, but, until one actually picks up a torque wrench, one does not know. And, even then, since everything is always changing, how can anyone really ever know anything when there is no such thing as a fact because everything is always changing, er... but that is a philosophical discussion for another time.... like in the evening after school at Mid-Ohio perhaps?
Happily I'll get to bug Coby about this stuff in person in just a few weeks and get all my answers questioned.Bug Cobie?! Now yer talkin' turkey brother man!! Count me in!! Can we tie him up and shave his eyebrows first?
Anway... whether talking or doing... or doing not... the song remains the same. One step at a time. Small steps.
So, which technique(s) were you unable to kinesthetically grok?
r
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How do I get the tires from the school before I take the class?? Will you be there doing tires at VIR on the 18th?
Hey Hank,
I would contact (phone) the school directly with important time sensitive questions like this one to be certain you get the information you need in time.
I know Cobie and JR get up here on the forum as often as they can but I think it is more difficult when they are traveling "on the road" with the school this time of year.
Cheers,
racer
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I am thinking about attending level one at VIR on 05/19th.Its about 3 hours ride from my place.I was thinking about riding there and then riding back is that recommended ? anyone done that before
This would be my 1st track day and i dont plan on going way fast just want to learn how to go around the corners.Can we setup and leave the bike at VIR the night before .
I have around 4000 miles experience under my belt and wanted to start by getting the right training so that i dont build bad habits or should i wait and get some more experience before doing school i surely want to do level one either in May or when school returns to VIR in September i just thought if i take the school now i would have whole summer to practice that
Also i was planning to bring a voice recorder to records classroom lectures is that allowed ?
Thanks
Hi Bobby,
I always rode my street bike to the school but used/rented the school's bike/leathers when I got there. However, I don't see any problem with riding your own bike to and for the school, I am sure many students do. Just be sure your tires are fresh and the bike is in good mechanical order. Personally, I would recommend fresh fork oil and brake fluid. Now that I am older (and wiser?), I change my fork oil and flush my brakes at least once a year; but, there was a time when I never bothered. You might want to reset your sag for full riding gear if you don't normally ride with full leathers and boots, etc (my gear adds about 20-25 lbs) and you might be using more of the suspension travel on track so you might want to dial another quarter inch out of your sag anyway, but, it probably isn't really critical if you are in the ballpark already. I'm just a perfectionist.
That said, I strongly recommend reading at least the first Twist of the Wrist book and being very familiar and practiced with the basic concepts and techniques contained in it before taking the school. I feel it should be required reading for any motorcycle rider, much less any rider taking the school. IMO you will get more out of the school track experience if you already have a handle on basic concepts like counter-steering and some degree of proficiency with techniques like braking while throttle blipping for your downshifts. Of course, If you don't have a handle on these skills, the school will certainly help you learn them!
Have fun!
racer
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Hey tweek,
Best advice anyone ever gave me for riding/racing: "Relax. And remember to breathe."
Sometimes when attempting to "grok" something, I find I am trying so hard that I make things harder by trying to bite off more than a mouthful, trying to take everything at once.
So, I try to pick just one thing and try to be very specific. Nobody knows what to say to, "I'm just not getting it". I can't answer that, neither can you. My advice is to be specific. Write it down. Make a list. Then make a plan for that one thing.
Don't worry about touching your knee down. Or how fast you are progressing. Or how fast you think you "should" be progressing. It takes as long as it takes for everyone. There are no "shoulds". I try to forget all of that and slow down inside my brain a little bit and think about just one thing at a time. And focus on just that. For instance... quick turn. This is the most important to me. How many parts are there to just that one thing? Reference points. Turn point. Off the brakes. Use your whole body to pivot turn. Body position and "hook turn". Two step. Smooth throttle. Apex.
Then narrow it down to a simple plan for just one thing... like choosing my turn point.
So... what exactly is it that you feel you are not quite getting about what we have been talking about?
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what exactly does this mean?? obviously higher corner speed while maintaining the ideal line is preferable so why do people say this? i always took it as a reference to movements i.e slowly shifting my body weight, slowly rolling on the throttle at apex etc.. and as a reference to perception i.e. looking through the turn to decrease the perception of speed or "slow it down" in my head.
to me, it should be: slow in=fast out
i havent signed my world superbike contract as a factory ducati rider yet so please guys tell me where im getting this wrong
The e-ticket is getting on the gas as soon as possible after getting off the brakes and leaned over. The slower, more controlled, you are on the entry, the sooner you can get back on the gas, the faster you will be in the corner and, most important, the better drive you will have out of the corner... which pays dividends all the way to the next corner.
Being a little faster for a short distance isn't as important as being fast for a long distance. Don't try to make up time or hang it all out for a short corner, there is little to be gained there. AS opposed to going just a little bit faster in a long corner or a straight away. Go fast in the fast parts and slow in the slow parts.
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Not at all. Classic highside. "Highside", by definition, is losing the rear and then suddenly hooking it up again such that the rear compresses really hard and then springs you off into the air when it unloads... which is exactly what happened to Lorenzo. He didn't steer too hard, he accelerated too hard.
Use the pause button on the slo-mo and watch closely.
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Hi kwh,
If there is "extra grip" left over, wouldn't it be preferable to use it to carry more speed, rather than use it to slow down?
(Aside from say a decreasing radius turn, of course.)
Ah! Sorry, I never saw your reply back when you wrote this!
Yes it would be great to carry more speed, but what does that mean?
OK, so you are a MotoGP riding god with more talent in your little finger than the rest of us mere mortals have in our entire bodies put together. And your chief telemetry technician comes and tells you that you aren't using anything like all the grip your MotoGP front slick offers you in the corners. What to do?
You you can try to turn ever faster, but there comes a point when your arms are moving as fast as humanly possible, and the bike is going from vertical to full lean as fast as a human can make it. Being a MotoGP riding god, you probably already reached this point. So what then if you still have lots of front grip in reserve?
OK, you're hypothesizing a situation where the ultimate limit of everything is the rider and the turn radius, ie. the tires are beyond human capacity to force a slide. There is more grip than you can ever use.
So then you can try and carry more corner speed. But at a certain point, you will be so far over on your ear that you will be about to ride off the edge of your MotoGP spec slick tyres and/or deck the footpegs etc, however much you shift your weight to try and reduce the lean angle. Again, you are probably already there. So what if even then you still have lots of front grip in reserve with your MotoGP front slick? Presumably some cheeky competitor will use that extra grip to ride under you before you turn and then use that spare grip to brake all the way to the apex while holding a similarly tight line, right in your way?So, is the answer (for our imaginary MotoGP riding god, not for us) to turn in at a higher speed than we otherwise would while quite hard on the brakes to make full use of all that spare grip?
He is turning in at a higher speed ... while quite hard(er) on the brakes... to make use of all that spare grip (that all of us have)... hmmm...
If the tires have ultimate grip, then the limit to turn the bike is the strength of the rider. In that imaginary world, I say go to the gym. The rider who can counter-steer the bike hardest will be able to corner fastest. Whether you are off the brakes or on the brakes, you still need to turn the bike and if the rider off the brakes is turning as fast as humanly possible already, how can the guy on the brakes turn faster? Not to mention that turning on the brakes is harder to do in the first place!
As for the cheeky competitor who gets under you on the brakes, I don't think he will be able to hold a "similarly tight line". Even with all this hypothetical traction, simply put, the lean angle and turn radius required of him to stay on your line is impossible. You are already at max! And once under you he has to turn TIGHTER than you to stay on your line. In that scenario, the only way he can turn faster or tighter is if he is going slower than you are. The solution is the same... drive under him on the exit. Whether there is infinite grip or not, it is still the same grip for everyone. And the bottom line is the bike goes faster with the brakes off. (Go figure. The ultimate secret to riding fast is less brake and more gas. D'oh.)
Seems to me that nothing much changes. If traction is not a factor, and the limit of cornering speed is the radius of the turn and lean angle, then the critical issue is still the transition to max lean... and the faster/sooner you can get down to it, the less lean angle you need for a given speed, hence, the more speed you can carry through the corner or the sooner you can start to pick it up from max lean and go hard for the exit and the next corner. The final arbiter of corner speed (and a fast lap) is still going to be how fast you get the bike turned in. IMO, all else flows from there.
I only ask the question. But it would explain the observed effect...Watching the world superbike guys go at it, late braking duels usually seem to end in a rear wheel slide entry (backing it in) to the corner, ie. the guys who are late braking, charging and/or trailbraking hard don't flick it in to get the bike turned. So, they end up blocking the corner but then have a lot of motor to accelerate.
Traditionally, the GP guys have a slightly different style dictated by the bike and the type of tracks they ride. I am told that it is difficult to put into words just how blindingly fast and powerful a MotoGP bike is. And how razor sharp and unforgiving its envelope is. The bikes are lighter and smaller, hence, somewhat less stable to boot. You can't manhandle them like a superbike. Yes, Gary McCoy and others have made an art form of sliding them, but, it is a far more precise and graceful art than what we see in superbikes. And there is a very fine line between having everything just right and just wrong. A good rider can ride around some issues on a superbike if it is not set up right. It is not so easy on a GP bike. Anyway.... the point is...
Larger, heavier, and more powerful equals easier to get away with certain things as the extra mass tends to increase period and decrease amplitude of the bike's reactions... and the longer wheel base also creates less/slower reactions to inputs and more motor gives the rider more options under acceleration.
As for what is going on in MotoGP with trailbraking these day I can't really say, I've only just begun watching the races on TV again, but, I promise I will.
Anyway, yes, using trailbraking to control suspension rebound is a viable and potentially valuable skill. And having the front compressed alters or quickens the geometry to a more radical rake and trail. However, it also makes the bike more difficult (heavier) to steer and reduces traction. And there are other techniques to alter center of mass and geometry and "hook" the turn. Also, consider there is more compression and loading from cornering forces than braking anyway. So, what if you came off the brakes in a controlled fashion prior to the turn such that the front was settled when you intiated the turn? Could you turn in faster? Isn't that the final arbiter of corner speed? Faster turn in equals less lean angle at a given speed. Faster turn in equals more potential corner speed. Faster turn in equals earlier exit drive. Faster turn in equals a faster lap, period.
(Hey... maybe MotoGP riders have their idle speed turned up so much they have to drag the front brake to keep from accelerating too hard...???
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Hi Tweek,
All I can do is repeat what others have said.
The quicker you flick it, the sooner you get it leaned over, the faster you change direction, the less lean angle you will need to complete the turn. The longer you take to change direction, the later you get to max lean, the tighter you have to turn to complete the corner and the more lean angle you will need to do that.
Look at the diagrams for the "hook turn" in TOTW II. This is key to less lean angle for a given corner.
How and where you "lock on" combined with getting your upper body hung off can move your center of gravity forward to alter the geometry and make the bike turn sharper, and... since there is more mass in your upper torso than your butt and one leg, the more you get your upper body hung off the bike, the more mass you get toward the inside of the turn to offset the COG and the less lean angle you will need to balance the cornering force for a given speed. Or, to say it another way, the more speed you can carry at a given lean angle. All of these techniques will help reduce your lean angle in a given corner.
Finally, being on the gas raises the suspension which increases ground clearance and will help keep footpegs and such off the ground while also balancing the front to rear weight distribution (60% rear/40% front) for max traction which, again, means more speed is possible. Getting back on the gas sooner not only means you are increasing speed sooner, it also means you can carry more speed outright because you have more available traction when you are on the gas.
Hope that helps.
racer
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Any quality brand tires will be fine. IE The school bikes are on Dunlop Qualifier tires, which are street tires and have more than enough grip.
Aside from "any quality brand tire" being "fine", do you think it is fair to characterize the Dunlop Qualifier as a "typical" street tire?
I've heard the Dunlop Qualifier described as a "dual usage" tire (for street and track), having more grip than a typical street tire. Even Dunlop describes them as having "race track-level grip and performance":
http://www.dunlopmotorcycle.com/
@ DMX
I would buy a set of Dunlop Qualifiers from the school. If I recall correctly, you even get a nice discount as a student.
That said, if you choose to run the other brand race tire (which I wouldn't), then the medium compound would be more appropriate than the soft compound for Willow Springs in June.
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I should mention a few more Kiwi's of note, some of whom I was privileged to race and travel with while living in NZ (and whose association was priceless on a personal level)...
WOW! I've only heard of maybe 3 or 4 of those guys and I consider myself to be pretty "cluey." I've only been to NZ once and that was for our 'southern hemisphere' wedding. (How about that sky at night: completely alien constellation!)
When you see the Southern Cross for the first time...
And the Magellanic Clouds.
And the Man in the Moon... UPSIDE DOWN!
And Invercargill sunsets that last for hours in December and January. And climbing out of the caravan at 3am to pee and the last glow of the sunset has just sort of moved back across the horizon toward the east.
That latitude makes for some interesting effects. One night after the Sun had set below the horizon, the underside of some broken mid-level clouds on the dark half of the sky (black and star filled) were being lit from below by sunlight from below the horizon. Flourescent colored glowing clouds in a black star filled sky. Like something out of a psychedelic Magical Mystery Tour. Outrageous. Of course the camera was back at the track as we were just "grocery" (um... beer) shopping in town. Well, actually, we were holding impromptu grocery cart races in the parking lot at that point... but... um... that's another story.
I also hooked up with a sailboat racing team while I was there and crewed several NZ Gold Cup races. One of which was an overnight race around the Hauraki Gulf accompanied by a school of dolphins and flourescent plankton flourescing off the bow under the full moon through the lines.... sigh. I earned an invite to crew an Auckland/Fiji open ocean race and.... sometimes I really can't recall why I ever came back.
I understand Burt Monroe's grandson was in attendance at our wedding but that's all I got.Wow! Burt Munro's grandson! How cool is that?!
Don't those Kiwis really know how to have a good time!?Um... what happens in NZ...
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And cheers to Keith Code and CSS ... Kiwi's in spirit all to be sure!
I offer into evidence the 1/3 page photo of the Britten on page 1 of the introduction to Twist of the Wrist II.
Sweet as...
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The 100 mph average is a common goal for racers at the Isle of Man races. I did not intend to connect it with Nurburgring tourist days. Sorry for for the misunderstanding. Ithought they used to have dyas where just bikes were allowed to ride the Ring. It's too bad if they don't. Bummer.
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I know lots of folks here have ridden M-O, so... whaddya think? What has been your experience?
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Her name isn't Sheila... is it? <g>
OK, seriously now...
I should mention a few more Kiwi's of note, some of whom I was privileged to race and travel with while living in NZ (and whose association was priceless on a personal level).
The first is motorcycle racing champion Midge Smart (dual Kiwi and Brit) and his wonderful family without whom my season in NZ could not have happened. And I can't fail to mention (and thank) Paul and Mandy of Trisail Racing (my sponsor in NZ and NZ HRC distributor), two wonderful people also without whom my NZ experience would never have happened.
The next is Dave Cole (NZ 250GP Champ) Trisail mechanic and teammate turning wrenches for Midge Smart 03-05 (NZ 125GP Champ, TT champ, National Series Champ, etc).
Next is Jason Easton (NZ F3 champ) and his engineer/tuner (whose name escapes me at the moment...arrrgh! but whose father worked with Bruce McClaren I believe). They spent a season kicking Ducati factory butt in Europe on their homebuilt race bike. My Kiwi experience and the Kiwi scene in general would not be the same without them, their skills... and their mad antics!
Dominic Jones who gave Midge serious competition on a 125 the year I was there and came to the US last year to race AMA.
Brian Bernard who spent some time racing here in the US and is currently (I think) sponsoring Dave Sadowski... racing in NZ! Brian is a super dude and a keystone in the NZ scene.
Shaun Harris (NZ and Isle of Man champ) was a fantastic host and hysterically funny (especially sharing stories of his experiences of the Isle of Man and world travels over a few Kiwi brews).
And Andrew Stroud (NZ champ and Britten rider here in the US) without whose dentist referral I would have been left to find emergency dental care in a foreign country on my own... lol. A nicer person I have never met.
Another big prop has to go to another former Kiwi teammate of mine who inspired me and inspired me to believe in my own abilities to design and fabricate... Neville Algie (NZ 250GP champ), who lives in Indianapolis and builds exhaust systems for CART/IRL and his brother who lives in Ohio and owns a company that fabricates carbon fibre composite parts for the Formula One circuit.
There are many others who deserve mention, but, I would be here all night.
And cheers to Keith Code and CSS for letting me mention these personal things here on their website and without whom my racing career, riding life and life in general would have been so much less... if not non-existent considering how many times over I owe them my life due to the skills I learned at their schools. Kiwi's in spirit all to be sure!
BH
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Thoughts? Comments?
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You're a lucky gii! Kiwi grrls rock!
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This is how car racers approach it...
"Turns 4 and 5 (The Keyhole) is a right-hand, double apex corner and the first apex is the red and white curbing on the right basically at the entrance. As you are braking and go past this curbing, the car should end up about a car width from the right side curbing. The left front edge of the concrete patch should be between the front wheels. Again, trail braking thru here will help rotate the car and get it pointed where you want. It's important to be patient here though because the track now slopes down hill. You'll want to get on full power, but you must wait until the car comes around a bit more. Steer the car with the throttle thru the corner. Once the car is pointed down the hill toward a late second apex (turn 5), you can now start applying a smooth throttle to exit the corner. This is the most important corner on the track as it leads to the longest straight and to one of the few passing zones at the end. You can use the curbing at the exit, but remember, it's extremely high and tends to jerk the car if you hit it. Make sure you have a good grip on the wheel if you plan to use the curbing!"
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In the meantime, it has probably been nearly ten years (pre-repaving) since I have ridden there and the turn might not be so clear in my mind as it seems. To my memory, there is a fairly significant elevation change of perhaps 6-8' feet roughly 1/2-2/3 of the way through the turn. I say significant due to the rate of change in that I would characterize it as a "drop off". The fall line for this drop off runs at something of an angle to the direction of travel from the outside toward the inside of the turn, that is not quite perpendicular nor parallel with the direction of travel...
heck with it...here is a photo:
OK... I think this is the exit of the keyhole. I can't think of where else it could be with open sky beyond the fence. The fall line combined with the racing line seems like it might create some positive camber... sort of like a "double fall line" effect in snow skiing. Sort of the inverse or reverse of Turn 5 at Road Atlanta where the uphill elevation creates positive camber for the entry?
Cool. Even though I have ridden and raced M-O numerous times and was perfectly aware of the corner's orientation wrt camber and fall line, I never considered the exit of the keyhole from the angle in the photo which illustrates it so perfectly.
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Thanks. I will.
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Hi babyknows,
I would suggest directing your questions to the UK/Euro CSS team here: http://www.superbikeschool.co.uk/contact.php
r
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Hi babyknows,
I would address your questions directly to the UK/Euro CSS team here: http://www.superbikeschool.co.uk/contact.php
r
Lean Angle == Turn Radius?
in Cornering and Techniques
Posted
You might find this post from another thread helpful: http://forums.superbikeschool.com/index.ph...post&p=5193