racer

Ah...I see you are running a HEAVY weight bike in a National series...if they go off, they go off. If that's what everyone else is doing/using, then I guess you gotta go there. Good luck mate.

Um...yeah. I should probably add a caveat and disclaimer... With the constantly advancing technology of tires and my own lack of 'recent' experience...as in I haven't actually purchased or ridden anything in the last several years...I should probably stick to more general and not potentially time sensitive info. Best advice, go by your trusted tire man's info. Most of my own limited knowledge was garnered in the last century, haha. Prior to 2000. And mostly DOT treaded Supersport tires for 400/600 classes and slicks for 125 or 250 GP bikes. Mostly, Dunlop(slicks and DOT) and DOT Metzler, maybe twice on Bridgestone slicks because they were paying but I didnt like them. I can't remember why. Maybe because they didn't last? When I said 'full race' compound I merely meant to distinguish from 'street' sport compound tires. Like I think were being referenced before. "Sport-Touring" I think. So... When I switched to slicks for the GP bikes that was another level and actually having a choice of compound as opposed to whatever the tire guy gave me was another thing. I do know or used to know guys, oops, girls , um...racers that only used tires for a day, like three /four cycles, whether they had a special tire or were just so much better than me(?) or had more money I don't know. My own practice was to run fresh tires for raceday scrubbed in one practice, tho lots of guys would do just a single scrub lap + sighting lap, way more work than i wanted to do constantly switching wheels. Maybe if I was a pro or had a mechanic or trusted someone enuf to touch my bike haha. In any case, I'm talking about slicks now (Dunlop), I would run last race tires for practice Fri/Sat up to about 8-10 cycles and never had a problem tho i could definitely tell the difference when i put on the fresh rubber Sunday. I did have the experience of running super soft comound meant for cool/smooth track on hot rough track being utterly destroyed in a day. Again, these are light or middle weight machines not superbikes. Bottom line, like I said, if the compound is hardened or worn, don't use it. As far as how many heat cycles to run YOUR race tires, ask the tire manufacturer or distributor, preferrably one who specializes in tires and is reputable. Way back in my day haha some tracks didnt have a tire guy or just a had a dude/dudette who sold some stuff and a few tires, nothing against him/her, but these guys didnt always have the best info. For Bridgestone slicks, ask Andy. PS As I said, I never enterd the lofty club that had race tires that only lasted 3 heat cycles. Being cynical, I'd be interested to know if you yourself have observed this to be true? Are they trying to sell you more tires? haha. Seriously, though I have heard of it and believe these tires exist. Just can't imagine spending the money to use them. I hope Bridgestone is sponsoring you. Do you race AMA National Superbike or World GP oops Moto GP? Chasing big purses I hope.

Oh, and a great big 'Howdy" to ya Willy Ballistic! Great pic..you haven't aged a day. And congrats on your racing...you inspire me to believe I have more riding/racing to do, yet. Peace

Thanks Willy. Would it be accurate to say that 'trail' is the distance by which the front axle trails an imaginary line drawn thru the steering head toward the ground? And that the difference in angle between that line and the forks is the angle of 'rake'? And that, like the wheel of a shopping cart or a 'caster' on your bed frame turned 'backwards', the wheel tends to stabilize itself by flopping around to follow or trail the steering pivot. And that a chopper's front wheel is unstable because the trail is negative? That the front axle actually 'leads' the caster angle creating a tendency for the front wheel to want to stabilize itself by flopping around to a trailing position? Like the wheel of a shopping cart turned around backwards? I always liked the shopping cart analogy because we've all had a cart with a wheel that is turned around backwards and flops back and forth trying to stabilize itself.

good gosh, what have i done? i'm going to go home and rethink my life...

This is why we have inserts for steering head now.

BTW - I believe there are California Superbike Schools in the UK. Hey Kalkat, Thanks for the invite to Texas, mate. I'm in Pennsylvania for the "holidays" with the family. Come January I'm probably gonna bugger off to New Zealand to go race sailboats or something. In the meantime, get "A Twist of the Wrist" book and get on a track where it's safe. I recommend Keith Code's schools as the best place to start. His team is professionally trained to teach you with decades of experience doing just that. The best of the best as it were. Me, Im still learnin them thar people/teacher skills things. Duh... Keep up with the math. It'll take you anywhere you want to go. Cheers

Indeed. Musta been some unresolved personal issue giving me an attitude and putting me in front of the computer at 3am "thinking" about it all and latching onto another math geek like me. Or maybe it's the snow on the driveway. Hmmm...time to go skiing. YAHOO!!

A clear definition of caster angle or rather rake and trail as it is referred to on a motorcycle...(as you can change caster angle on a car without altering ride height, more specifically the length of the fork, and hence trail) would be helpful in understanding exactly what is going on here and why. Or at least the next step in my mind. I'm too tired to get into it now, but, I'll give it a go tomorrow or next day.

PS: I've modified my original post a bit in an effort to clarify some of my late night stream of semi-consciousness.

Ah, my mistake, dude. You go get 'em. Via con dios.

kalkat, my friend, your equation...or should i say theory...fails to take into account several factors...mathematically speaking...like the rotating mass of the crankshaft ergo forces of engine braking or lack thereof, weight transfer, friction with the road, the bike's suspension, gyroscopic forces, and most importantly...rider input. it asks me to accept several assumptions as 'given' which simply aren't so. for instance, your premise of m*g*x being the 'force' that "makes a bike fall into a corner". well, the fact is...bikes don't fall into a corner. simply put, left to their own devices, excluding long term entropy of the system (like the bike losing all its v) bikes will go in a straight line unless acted upon by another force, such as...the rider. (due to the gyroscopic force of the rotating mass of the wheels and tires) a certain amount of force applied to the handle bar is required to push the bike over at speed. no doubt gravity helps. but i can overcome gravity with the application of enuf reverse angular moment applied to the handlebar to push the bike back up. and then the steering geometry changes as the forks compress under braking, and the contact patch of the front tire gets bigger...and then...and then...and then... excluding these factors in an effort to "simplify" is like trying to simplify rocket science by excluding heat. it ain't real. the simple fact is the entire system is dynamic in many ways...nothing short of calculus will work with enuf accuracy to describe it mathematically in anything approaching a realistic fashion...and any physicist will tell you...you don't really need the numbers to understand the theory. but you will need to actually ride a motorcycle to prove anything. naming isn't knowing. hey, it's 3 am, i've been up since 8am yesterday. i'm way too tired to do math. go do the experiment with a stop watch and tell me how it works out. guten nacht ps in the nicest of ways...welcome to the family. it's anything but simple for us mere mortals. try reading twist of the wrist. the man's kinda been researching the stuff and proving it for, well, a lifetime. then prove it to yourself. or disprove. i don't ask you to accept anything at face value. lord knows i don't.

Not to insult anyone's intelligence... But for those among us who might not know... There's a big difference between a tire's pressure "hot" and "cold". Tire pressure is set while the tire is 'cold'. Cold pressure is measured/set with the tire at ambient air/room temp in the shade. Re: LDBANDIT finding 34 psi in his tire. If this was a 'hot' tire, the 'cold' pressure could easily be 30 psi...or less. Also, there can be a big difference from one tire gauge to another. As with so many things, you get what you pay for. I have on occasion found a relatively accurate gauge over the counter or on the end of a hose...but usually not. Invest in a good one, and always use the same gauge. It matters. (gauge, guage..? darn, i think i misspelled that more than once in another post. how embarassing. way past my bedtime...) Street compound tires will wear much slower than race compound and are designed to wear off old rubber to be replaced by whats underneath. The compound is designed to last thru many heat cycles. Bluing can be caused by more than one thing. Bottom line, it's rubber that has lost it's oil. The rubber is 'cooked'. Finding a narrow band of blue at the edge of the tire is not abnormal. It does not mean the whole tire is 'cooked'. The next time you roll it over to that point the old stuff will wear off and newer rubber exposed. Theoretically. Regarding race compound tires... Rubber will also react with the oxygen in the air to turn blue. Another rule of thumb: stick your thumb nail in the rubber. If it comes back, that's a good thing. If you can't dent the rubber with your fingernail...bad. Learn to read tire codes. Especially the "born on" date. Compound codes and country of origin might be nice to know as well...but, the rule is two years old. No matter what color it is. As far as the: "You can use that tire even though I can't cause I'm faster than you" ...might be true but makes about as much sense as buying a cheap helmet. What is your head worth? And at the end of the day if you push your limits like you should... how do you know what the limit of that worn out tire is? Aren't we trying to go faster? That being said, if the whole tire is electric blue and shredding and melting on the sides...it's cooked. Don't use it even if you are a novice. And as Dale Quarterly said to me after asking what happened when I fell down in front of him in practice at Mid-Ohio..."You can't cheat the tire man". Thanks Dale. Good advice. But you can crash in practice. Only you know what your life is worth. What is the value of a practice in which you worry about your tires being old? In general, a full on 'race' compound tire will give consistent race grip through about ten normal full heating and cooling cycles. Really hot tire warmers can cook a tire. That being said, the first couple cycles will be a bit better, the last two a bit less. After ten, use at your own risk. Fine for the street, maybe very careful practice if you must. I don't recommend it. In the old days, certain brands were known for progressively and predictably losing grip over a few more races. I knew guys that ran the same tires for a half season. Turned 'em around and ran em backwards when they got worn on one side. Other brands were known to 'go off' like a switch. I used to run whatever on Friday practice, to save money and cause I wasn't gonna go that fast...and been rather surprised on heat cycle 11 when I found my self on my arse thinking, "what the ...?". It's up to you. Just my experience. Lastly, storing tires near an ozone source will also effectively cook a tire. Electric motors such as you find on your furnace blower for instance. In your basement where you might be tempted to or already be storing your tires. Or electric air cleaner/smoke eaters. Air conditioners, refrigerators, electric compressors in the garage...you get the idea. That's my 346 cents...

Keith has given away the big secret. Well, half the secret...to the perfect launch. I have used this exact technique to holeshot the field from the third row more times than I can count. Of course, what to do just before going WFO is still a subject of great debate... (You could have sent him an email.) Cheers

What was the air temp on the ride in? Sunny? Windy? Though increased pressure is good for riding two up, I don't know what the standard pressure might be for BT014's on a YZF1000. But I tend to agree with sanfret. 35/37 sounds a bit high for normal single rider. Also, though I do occasionally meet an over the counter or attached to a hose air guage that reads fairly accurate, most do not. Just a thought. What are you using for an air guage? Invest in a good one and use the same one all the time. This is all predicate on "a squirt of air" seeming to "sort it out". Sunny day, greasy city streets. Recent accident or spillage at the roundabout???? All things being equal, sounds more likely. Especially, since all was good on the motorway. Sounds like a localized phenomena of the space/time continuum... As for the shock...well, with two up, albeit "a tiny pillion", things like compression damping could have an effect on traction under acceleration, and spring preload? Tiny as your wife may be, even at 90 pounds she's plenty of weight to create significant differences in the suspension (sag, geometry, etc.) as well as changes in handling. Perhaps your owner's manual has suggestions for standard and two up riding adjustments for your suspension and tire pressures. If you don't have one, get one. It's no guarantee, just a good place to start. cheers

Anybody ever ride a dirt bike? How much time do you spend "sitting" on the seat? If you're doing more than putt-putting around the parking lot...not much, I'll wager. So, where is your weight in a turn? Inside peg, outside peg, heel, toe...whatever. I can tell you that some of my weight is under my thigh on the seat, but, generally on my feet on the pegs. Unless I'm tired and getting lazy. Being on the pegs gives me a sense of being in control. Riding the bike as opposed to the bike taking me for a ride. Prepared and able to make changes. And if I'm going to move my butt, I pretty much need to be on my feet. Because, frankly, the only other point I can support my weight would be my hands...on the bars. Bad deal. Make sense? To accomplish this may take some practice if you are used to tooling around on the street. Try keeping your butt "curled" under your torso. At least that's what it feels like to me. A photo is a freeze frame. Keep in mind that centrifugal forces are at work as well as gravity. He doesn't fall off because his weight is being pulled 'sideways' (laterally) as well as 'down'. He isn't "hanging" on the bike in the literal sense. Though there maybe a bit of weight on the seat, I don't think it would be friction holding him up so much as lateral g's pushing him 'down' onto the seat. Keep in mind also, if you aren't racing yourself, that the lateral g forces at racing speeds far exceed any you should be experiencing on the street. My fastest school times on a 600 were 10 seconds a lap slower than my slowest race lap a few years later...on a 125. And do you see how long Colin's legs appear to be? Well, they are long, but, look at where his footpegs are located. Not just 'rearset' but also a bit higher than your average sportbike. It is a matter of preference, but, higher pegs do allow for moving around and off the seat a bit easier. I think this may contribute to the 'gangly' appearance or the seeming unnatural distance between his leg and the bike. And consequently, long legs + high pegs = more leg leftover after butt width movement off seat. I used to have a set of pegs so high on my 400 that I looked like a horse jockey. And the first time I got on a factory 125 I had to actually lift my leg with my hand to get my foot on the peg at all. I never bothered to glue the seat pad on my last tail section because, frankly, I never sat down. I learned at racing school that the only time you sit on the seat is to have a rest down the backstraight. Then Rich Oliver showed me I'd do better staying on the pegs with my butt off the seat after all...aerodynamically speaking. But that's another story...

oh, and all apologies to homegirls and dudettes. unintentional gender specificity....was, well...unintended.

oops... Steps one thru four were mistakenly deleted by the editor.... 1. Read the Twist books. 2. Go back and read them again. 3. Repeat steps one and two. 4. Attend the school. ad infinitum...

uh..oh...HEY KEITH!! It does say 'Keith's Corner' at the top doesn't it? And there I go responding to replies...what was my intention...? Well, I'm in deep and sideways now... CaptGino, I believe the chapter I was referring to is called 'Seeing the Big Picture'. Or something like that. Twist of the Wrist. The original...guess I'm old school. Using RP's to form sub-procucts and products is NOT "cheating". When you visit a new track you simply need to start from scratch. Learn a new set of RP's. Walk the track. Get to know it. Make friends with it... Then there is the idea of 'target fixation' or 'you go where you look'. And between these two ideas is what I'm driving at. "See" the RP without looking at it. Maybe? I'm not watching you so I can only guess. If you find yourself needing to lift the bike mid-corner, are you turning too early? Need more speed? ...somehow? Might you be going slower than you can because you aren't comfy yet? New tracks take time. Check it out. Are you watching the homeboys' lines between your sessions? Try cornerworking a new track...especially if it has limited spectator access to the viewing areas. Try following a 'local' dude in practice. Maybe you ask him first and make friends...hmmm. As for thinking while you ride...probably best to think before you ride, make a plan and work on accomplishing it. Perhaps taking stock while you breath on a straight away. "Did it work? Maybe I'll try option two." I haven't watched 'Val' since 2002 or mid-2003 as I've been living at a monastery, overseas, or in some foreign country without cable access...but prior to 2003 I've seen pretty much every one of his races back to the 125 WGP's when his hair was half way down his back and he wore a superman cape to the podium...so I'll have to dig up some tapes and do some watching/thinking to speak about what I see in some meaningful way. As for what he thinks about...I can't say as I never asked him. And if I did, would it be in his interest to publish just now...? At my home track, I catch myself thinking about my grocery list down the back straight...as do many others. But that's another story... Frankly, I think Rossi would be hard pressed to explain what he does in a step-by-step 'how to' fashion...but, I can guess that even though he might be thinking strategy far ahead, as for his riding, he's pretty much here/now and looking just ahead. Only he could say... Mere mortals, best to follow steps 1-4. As for 'vague intentions', I'd have to start with seeing the beauty of the machine, the track and yourself. All else flows from that, dare I say, love? (What a hippie freak!) Hey, you wanna know about the force, you'll need to attend the Jedi academy. In the meantime, enthusiasm, excitement and attitude is everything... Peace Brother Man.

uh...taking exception to the "move your head not your eyes" advice.... when performing the "two-step" method...yes. however, recall Twist of the Wrist ... oceanic vision or awareness (can't quote as i don't have the book handy, but...) moving your attention around without moving your eyes OR your head. remember the classroom excercise of keeping your head still and your eyes pointed at one spot on the wall...while moving your attention around the room? imagining a string attached to each corner? well...i believe that particular exercise and class were at mid-ohio around 1988, and the champ we talked about was wayne rainey...but, i do remember this subject being covered in the book. so, aside from the 2 step method of shifting attention from entry to exit of a corner, i believe on this particular issue of "losing touch" with awareness of current location in time and space....that focusing too hard on any particular spot may contribute to disorientation, you can't shift focus of your eyeball that fast. by the time you take a static reading of your position it's too late. your position has already changed. and will continue to do so in process. a dynamic process. freeze frame is good for some types of analysis, but...chances are you need all the dollars and cents of attention you can get....for riding. in any case, i digress, as usual.... practitioners of some martial arts refer to a middle distance or almost non-focused gaze, the eyeball is focused neither near or far, but at the middle distance allowing one to more easily shift your attention or awareness. but...it's in the book, Twist of the Wrist. excercise: i like to run on railroad rails. yes, run. walking can be almost more difficult because it's too tempting to look at your feet or just ahead of them, while at speed, there's no way...great for balance too. talk about using the force.... also, new tracks vs home tracks... yes, they do force you to think again don't they? good luck

No matter how well you know a public road/highway, it's still public. It is an open and uncontrolled environment. You have no idea what might be around the next bend on YOUR side of the road from one moment to the next. And, aside from that niggling distraction in the back of your mind stealing your attention, there's no ambulance or safety crew to pick you up when the inevitable occurs. It's a great place to feel the exhiliration of cheating death...it is NOT a good place to work out finding the extreme edge of you and your bike, ie. goal of scrubbing tire edge or touching footpeg for it's own sake. Lean angle might be a bragging point, broken bones might be a trophy of a war wound with the gang of street squids, but, at the end of the day...what is your goal? There's no substitute for the real thing. Get to a track. Dude, if you are still alive...chances are there's some sort of feedback of impending doom that your body/unconscious mind is reacting to. TRUST your feelings! The only way to really get a grip on the situation is to ride a bike that has been professionally prepped on a closed course to compare. I'll never forget the feeling of getting back on my own bike after my first day riding a professionally prepped Ninja at a Keith Code School.... The feeling of "WHAT THE *&%#@!?!?" was overwhelming. The reason for your so called "lack" of lean angle could be any one of or combination of bike/rider factors. And like any good trouble shooting guide...start at the beginning, process of elimination, one thing at a time. My advice...eliminate the bike factors, get to the source. Sign up for and ride a Superbike School bike. I guarantee you by the end of the day ....well, you'll see.

The only time I've experienced extreme front tire tearing was while attempting to compensate for lack of front traction on a fast abrasive track by lowering tire pressure to ridiculous numbers like 20 lbs. when the culprit was actually too soft fork springs. The low pressure created extreme carcass flex leading to overheated rubber compound. Don't know how much the soft springs and pushing front contributed. How's your traction?

It's my opinion that the best source of riding information is Keith Code's schools, books, etc. Best source of racing info...clubs, schedules, news is Roadracing World magazine and website. When it comes to info on suspension/bike set-up.....I go by the old wisdom... If you wanna be a winner....ask a winner. Or a pro. Everyone has their personal guru for tech info but chances are instructors/technicians at the school are a safe place to start. You know they aren't looking to sell you a new shock absorber.

Hey M1, can I call you M1? What is equilibrium as it relates to front wheel/steering head and why is it toward the inside of the turn? My intuitive gut feeling is that it has something to do with the width of the front tire being smaller than the rear and perhaps the offset of the steering head angle ie. rake/trail...but you seem to know... Cheers.

In my opinion... Visualization techniques are a great way to see a goal. A goal is kinda like a destination. Where you wanna be. Kinda hard to get THERE if you don't know where HERE is. What's the next step? Which way should I go? Even a map won't help if you don't know where you are. Getting a clear picture of what you ARE DOING NOW is the only way to help you decide what to do next. Where did you roll off the gas? Where did you apply the brake? Where did you release the brake? Where did you turn in? Where were you looking when you did? Answer these questions and you get a clear idea of what you are doing now. And you have something concrete to work with. Brake sooner? Sooner than what? Turn later? Later than what? Twist of the Wrist explains techniques for doing this. Reference points, products, sub-products, etc. Especially, techniques for "seeing the big picture". Moving your attention around without moving your eyes to notice things like reference points without "fixing" on them. Get the book. Read it. Eat it. Sleep it. Live it. Just do it.