racer

i'm sorry. jef4ry can't answer just now. he's outside shoveling snow. please leave a message...beep. oh it's nice to live in texas where the sunshine never stops, i reaaly wanna go there but i can't afford the cost.... (sung to the tune of yellow rose of texas) silly sunday. get a sponsor. visa/mc/amex/discover are NOT sponsors...

keyhole at mid-ohio....?

last word walking out the door til later... by no means do i have a proof for any of this...it just sounds good to my ear or feels on track to my gut. but truthfully, i might as well being trying to sell you some real estate in florida. hence why i ask for the input of an expert to sort my meandering late night stream of semi consciousness. just rather try to think it thru than quote a quote of a quote of ... i'd be grate ful if someone said "you're spam dude." the forward momentum is all conserved and sorted to corner speed and here's the math to prove it.

I was addressing the idea that a higher c/g gives 'gravity' a longer lever so a bike will turn faster. Stated by someone regarding kawasaki's changes to the ZX10. And playing with the idea that gravity might not be the significant factor in turning faster. Znd that perhaps that moment arm has more to do with the momentum of forward inertia...as opposed to gravity. AS it relates to lean angle and the Bozdijar's questions and the answers provided by you? Quoting someone named datadan from cycleworld post? I was too tired to play with his math last night but the bottom line seemed to be that the sideways force balances the down force...hence the bike don't fall over and c/g height is irrelevant. I have more to say about that but no time now. In any case, he Dman, made some statements that I disagree with. Like Centrifugal force causing highsides...I was being a bit of a wiseacher, but I think it's important to be accurate about all that. And why I don't think gravity is the force behind countersteering a bike which may or may not have much to do with c/g affecting turn speed...but whatever the answer is ...I think it matters to know what the deal is. Was it really so much nonsense? In any case, I just logged on to see if anyone had any direct answers to any of my questions or refutations to my ideas. I don't have time to go back and read thru it all just now as I'm out the door for my one night out a week...yipee. Cheers. Not that my "theory" was well developed or anything. Just more like thinking out loud. Hi Kal kat. Yeah, you right. I can't help myself. pushing my limits. b cool

And...Rossi is overcoming gyroscopic forces to boot. Gravity? Riiiight. How long does it take a ghost bike to fall over? Seems like a slow motion replay to me. Going, going, going...going...still going a little...and...boom, gone. Once the bike is tipped it seems gravity would come into play, perhaps with diminishing effect relative to speed (inertia) or the force with which you countersteer...until you release the bars, when the front wheel finds equilibrium and starts to track, driving the forward momentum to the outside of the turn to create lateral g's and balance gravity... So, what happened to the momentum (inertia) of the bike's downward 'fall' into the turn? Is that energy translated or balanced by "lateral g's" but doesn't that leave something left over? If those g's balance a certain speed and lean angle won't the downward inertia require more to catch? Hmmm... Time to read up on gyroscopic force and the mysterious world of angular momentum...oo aaa. Any physicists or engineers out there? I'm just going by my gut here. Please correct my thinking before I confuse everybody. Everybody else that is...

There's no such thing as centrifugal force. Nor does it cause highsides. When describing an arc, due to rolling around the inside of a drum, the inside of a gravity well, or the inside of a mc tire...inertia will cause a centrifugal effect. Highsides are another effect of inertia. Usually the inertia from sliding sideways being suddenly released by the rear wheel hooking up and the compressed rear spring adding its energy. I can highside a bicycle from a crossed up nearly straight up and down position traveling in a straight line using rear brake. No 'centripedal' anything. Why does a car roll and flip when you yank on the steering wheel hard enuf? Gravity? Will it roll more/flip sooner if it's taller or top heavy like a van? Yes. Is that because of gravity? Why does an ice skater extend their (moment(um)) arm before a spinning jump? Where is that momentum coming from? Inertia. What is countersteering? Why does it not work at slow speeds? Perhaps because there isn't enuf lateral g "centrifugal force" (INERTIA) to knock it off balance? Why doesn't it work at hyperspeed? Perhaps because the gyroscopic forces of the wheels are so high they restabilize the machine enuf to overcome inertia? It seems to me that the driving force of knocking a bike off balance into a turn is inertia. Countersteering up again would also be driven by inertia. I'm thinkin that lever is being acted upon by inertia. Maybe once it's over, gravity helps or things balance out....but... Sorry, my gut just can't get beyond the mass of a mc moving at speed being less force than 1g at 30in. What's that deal...hitting a brick wall at 40mph is like jumping off a ten story building...or something like that? What takes longer? A standing still bike tipping over from gravity, or Rossi flicking it in? My imagination says the static bike will take longer... But what do I know?

OK. If one basically steers the wheels out from under a motorcycle, is the bike falling toward the ground or rolling along the z-axis? And is it doing this because of gravity????? I think not. As I have stated my opinion before, I believe gravity may assist, but, I believe the overiding force responsible for a bike leaning into a turn is the force applied at the handlebars. As I can overcome gravity and gyroscopic force by standing the bike back up. If the bike "falls" into a corner, why does it not hit the ground? Must you "catch it"? Or does it go over as far as you push it, a controlled roll? Did Kawasaki raise the motor to raise c/g ...or to move c/m closer to c/r? I mean how much did they raise it? A couple inches? And THAT is going to make a BIG difference in how fast it flicks because of gravity having a bigger lever??? Hey M1! Where is c/r? Which brings my next question... Why does a lower c/g require more lean angle? I don't know. My brain has been wrapped around sailboats and airplanes and I only have a few minutes to think about this, so, please set me straight at your leisure or I will track down this Tony Foale's book and edumacate myself. And maybe I'll grab Twist II and Soft Science while I'm at the library. About time I give them a read as well.

Being that we're so close to the winter olympics... I find myself thinking of a figure skater spinning in place with their arms extended. What happens when the arms are brought closer to the body? The skater spins faster. Hmmm. However, in this picture, the skater is ALREADY spinning when the arms are brought in. (inertia/angular momentum, etc) Where are the arms when the skater INITIATES the spin? Are they extended? Are they extended more before a spinning jump that requires more effort? How much effort needs to be expended to turn a motorcycle? Can a rider expend a bit more effort to capitalize (small investment/big return) on a lower c/g (or c/mass being closer to c/roll)? If the c/r is not at the contact patch, is it advantageous to think of a motorcycle 'falling' into a corner? And, if the c/r is not at the contact patch, where is it? If one is travelling perpendicular to a gravity field, what happens to 'weight'? When you run, do you feel lighter? In addition, considering gyroscopic action, how much does a bike at speed really 'fall'? I agree that the COMBINED 'c/g height' (of bike and rider) is paramount... With regards to getting around a turn at a particular lean angle and speed (for a given bike/rider combination), something about a sidecar monkey tickles the back of my brain...

Oh...you were serious about the trike...I thought you were being politely offended by my question and poking fun at me. I'm new to this computerized form of communication without aural/visual cues like facial expressions or tone of voice, etc. So, forgive me again and please bear with me. I'll try to give the most serious and sincere effort at explaining my "perception of reality". But I don't have time to get into it just now. Vacation is over and real life beckons... In the meantime, think about road bicycle riders/racers like the Tour de France. They tend to coast through the sharper corners and when they bite it, it's the front wheel that washes out, eh? As for NZ...I was planning to head back down under from the states this month for work/play/friends' wedding/etc. but might get 'stuck' here. So, we'll have to play it by ear. In any case, I've never visited Australia. If I can swing it, I'd love to come there. Sorry about the Fosters. It was the only OZ beer I could think of. I know how testy you boys can get about your second most favorite thing...

"a little more plainly", eh? hey mate, don't call me surely... alrighty then, can you come to auckland in feb for a speights on me or do i have to swim there for a foster's?

ok mate...please forgive me and my frustration as i cling to my own perceptions of so called reality... I'm gonna have to get back to you when i stop laughing...trike...good answer mate

http://www.glenbrook.k12.il.us/gbssci/phys...laws/u2l1a.html This page is titled "The Big Misconception" and is absolutely awesome.

Newton's First Law of Motion. Also known as the law of inertia. Webster's definition: a property of matter by which it remains at rest or in uniform motion in the same straight line unless acted upon by some external force. Though, from a physics standpoint, it would be more accurate to say, "unless acted upon by an unbalanced force." Here's a cool website to check out: http://www.glenbrook.k12.il.us/gbssci/phys...laws/u2l1b.html Actually, if you google up "inertia" there is tonnes of stuff regarding this subject. In the meantime, try this... Imagine the corner is steeply banked. In this scenario, the bike's path would still be a straight line as seen from directly above. So, relative to the pavement, the bike is still straight up and down. Right? Well, as it relates to f/r weight distribution under deceleration, there's really no difference in a flat corner. The bike is still moving forward, whether straight up and down or in a corner, makes no difference. Inertia rules hand in hand with gravity. Tell me this Woody...What would happen to your weight if you applied the brakes in a corner? Would it be evenly distributed over both wheels toward the outside of the corner? Or would it be distributed in a straight line forward toward the outside of the corner? The funny thing is...I'm working all of this backwards. What I mean is, I didn't learn this from a book and then go riding. I learned it by riding (and crashing) a motorcycle or bicycle. And now I'm going backwards to explain it. Which makes me want to ask a question... What kind of bike do you ride, Woody?

Glad you are OK dude. Sorry I didn't ask before. Anyway, I don't mean to say that the changes you made were wrong or bad. Only to indicate that those changes would more than likely make the bike feel different. Some people change ride height quite a bit from "stock". And run different size tires than what came on the bike. I don't mean to imply that you should lose the newer tires. And realize that going back to a 180/55 while keeping the lower profile front will effectively decrease the front ride height a full 12mm. Instead of the 8mm you have now. I'm all for experimenting. It's my opinion that many bikes need more rear ride height or steeper steering. All I say is be aware and be prepared. Good luck! And watch out for those rock dogs! PS I'm thinkin' lotsa folks probably run F4i's at the track and might have much more bike specific info about how they might alter geometry or what size tires they run. Any help out there?

I was cornerworking the return of the AMA National Round at Charlotte Motor Speedway back in nineteen something or other and there was this guy named Freddie who was making a comeback effort of his own riding a Honda superbike for a couple of brothers. I, like so many others, was really pulling for Freddie. Imagine my horror when he fell down on the first lap of the superbike event. Right in front of ME. If I was disappointed, he was VERY disappointed. While he helped me to push his bike out of the crash zone and lean it against the fence, I asked him what had happened. He told me someone in the pack had bumped him off. A few weeks later, I tracked him down in his trailer at Mid-Ohio to return the gloves he'd left at my station back at Charlotte and to request an autograph. While he was signing my white Honda hat, I asked him how he was feeling. He shrugged, grinning a little sheepishly and said, "Ah, nothing a little throttle control wouldn't cure." My favorite story would be the weekend Jerry W. showed up at Bridgehampton with his brandy new Ducati 916. Like number 24 off the assembly line. Proudly being the first guy on the block to own a beautiful shiny red 916 and having the audacity to race it, all of his friends at the track felt it would be the right thing to do to put Jerry's pretty new Duc under shelter for the night... since Jerry had gone off to sleep and left it outside with nothing but a canopy for cover. Well, you know how those onshore breezes can pick up the sand and scour a new paint job...right? Besides, what if someone stole it? Anyhow, we found the perfect spot in the little tool shed. Which measured about three feet square. Of course, we had to stand the 916 up vertically on the rear wheel, nose in the air, to make it fit; but, we were confident that it would be out of sight and harm's way. I remember thinking as we walked back to the campfire that if I didn't know where Jerry's brand new Ducati was, I'd never think to look for it in that tiny little shed. Boy, Jerry sure was lucky to have friends like us.

Hey RC! Since you specified "anyone wishing to chime in"... In my opinion, the sooner the better for you to get to a Keith Code CSS session. If you're looking for a reason NOT to go...I can't think of one. They are entirely prepared to teach/coach every skill in the book(s) one on one. And, they are the best. In the meantime, my opinion is...'counter steering' and 'front brake/blipping throttle for downshifts' are good skills to work on while you prepare for your first school at Mid-Ohio in August. Ah...Mid-Ohio in August...what a great choice. Pardon me while I re-live some of my best memories. Be safe, be there, BH

Tire spec's are expressed as a fraction called aspect ratio. Width/percentage of width. 180/55 means 180mm wide by 55 percent of that figure tall. Or 99mm. When you swapped the rear you lost about 4mm ride height at the rear. Significant but not huge. However, when you swapped the front you lost about 12mm of ride height at the front. BIG difference. So, yeah, definitely changed the geometry. Overall loss of 8mm at the front. No doubt it felt different. Overall geometry effect would be steeper steering angle. Quicker turning and less stable at the front. Additionally, both tires being lower profile would also feel different. Whether it would significantly change the contact patch or flickability I can't say without intimate knowledge of said tires' construction/characteristics. Which raises another question. Were the "new"-er tires matching brand/model? Were they the same as the one's that came off? There's more than size to consider there re: handling characteristics. Anyway, I can't say this caused you to fall down. Maybe you just hit a slick spot. But all things being equal, it would certainly have changed the handling characteristics.

You seem to have a good understanding of the idea that slowing down while traveling forward in a straight line will shift weight forward. And you seem to understand that "cornering forces" will slow a bike in a corner. Well, even in a corner, the bike is still traveling forward. Right? So, if you are slowing down in a corner, the weight still shifts toward the front wheel. Get it?

You're quite welcome, Stuman. And thank you. OK...My mistake Woody. With the possible exception of a sudden seizure of a 2 stroke GP bike, or getting stuck in a false neutral, or the 'coasting races' I've heard about (conducted by nuts in neutral gear with the motor shut-off going downhill), I cannot think of any situation in which I would intentionally "coast" through a corner with the clutch pulled in. Hence, my assumption that you meant coasting in gear. That being said... If one attempts to coast through a corner leaned over with the clutch pulled in, then, yes, the "cornering forces" will dominate and generate frictional resistance at the tire/pavement contact patch(es), slowing the bike. However, inertia (the tendency for the bike to want to continue in a straight line toward the outside of the turn), and the fact that you are now slowing down, will also bias that resistance (weight) forward as you attempt to negotiate the turn. Right up until you run off the track... So...No. Coasting thru a corner (with or without the clutch in) will not result in a "constant speed" balanced 50/50 weight distribution. Or it's equivalant. Once the bike is turned, one must "crack the throttle" to stop decelerating and shift the weight bias off that front tire. And continue accelerating smoothly to redistribute the weight bias to the rear wheel in order to maintain positive control and negotiate the turn as fast as possible. Which is MY entire agenda on track. Here's an interesting thought. I've heard it's possible, after getting the bike leaned over and back on the gas, to complete a turn with the front wheel in the air...while still leaned over.

I was unaware Rossi had published. Truthfully, this website is my only real contact with the sport lately...aside from an occasional foray into the want ads at RRW or FATBAQ. Or checking up on my buds on the Kiwi scene. Thank you for the heads up. It sounds very interesting.

A couple thoughts re: "getting the maximum engine brake out of every gear..." 1. Brake pads are way cheaper than engine parts/rebuilds. 2. It's sorta meaningless when I have the rear wheel in the air. Moderate braking/deceleration shifts most of the weight to the front wheel. Heavy braking can move all the weight to the front wheel. In either case, max engine braking will cause the rear wheel to skid. 3. Even under less than max brake conditions, I prefer to keep the bike in the highest gear possible leaving the suspension as free as possible to do its job: absorbing bumps and keeping the tires in contact with the pavement. Using the engine as a brake will bind up the rear shock. 4. Even in a non-racing street situation, such as a slippery intersection, you still maintain far more control by modulating the rear brake rather than trying to modulate the clutch to control engine breaking...I mean braking.

Actually Woody, the bike slows down when you get off the gas and begin "coasting". The biggest reason is that your speed is being used to drive the engine around with no fuel in it. Forcing air thru valves and compressing it with no real power stroke to push the motor round except the barest minimum needed to idle and practically working against a vaccuum. This is commonly referred to as engine braking. The road driving the motor as opposed to the motor driving the road? But even without that, gravity and friction with the road and rolling resistance in the drivetrain (wheel bearings, chain rollers, etc) will slow you down to whatever the idle rpm would support. Even if you pull in the clutch, you are still slowing down. Same as driving a car. Take your foot off the gas and your weight is thrown forward, eh? So, no, the bike is not at rest equivalant weight balance while "coasting". Nor does the bike slow down "purely from cornering forces" while drifting or coasting. Hope that helps.

Some things to consider... If you intend to learn to race and/or go racing, the KISS philosophy allows you to focus on your riding. The less time, money and attention required to maintain the machine the more time, money and attention left over to learn to ride. There's nothing like being able to roll it off the trailer, add gas and go. At the end of the day, you put it back and go home. By this philosophy...four stroke, production stock. Least maintenance, most riding time. Next is...how many classes can you run with it? You can always bump up...but not down. not just size but modification level. Most track time vs effort to get to the track. Twin vs. Four cylinder. Well...less cylinders, less plugs, less gas...less maintenance...less to rebuild..something to consider. More torque, less horsepower maybe...definitely easier to ride. More fun per dollar and lap. Less emphasis on shifting gears perhaps as the torque allows you to maybe get away with using one gear where others use three. Unless you are a large person, 6' and 170lbs +, starting with a small bore machine on the track allows the most forgiving and fun experience. Least amount of high-side risk. This is my opinion. But...you do eventually want to learn throttle control and roll on power wheelies...so...'why wait' might be another way to look at it. Might as well get to it. Something to consider...modern 600's make more horse power than my GPz750 superbike and weigh less than my FZR400 race bike. Basically the equivalant of a factory superbike of fifteen years ago. They are incredible machines...they are anything but tame. I and many racing schools recommend going as small as is reasonable. Again, most attention left over for learning to ride correctly. maintaining corner speed as opposed to using the engine to overcome mistakes. Not being overwhelmed by 120 bhp on a 375 lb machine. A two stroke, while light and fun requires a good bit of tuning time and knowledge. Chances are you'll spend most of your time tuning and learning to tune. And suffer from a bike that may not run right at any given point in time. I'd wait on the 2 stroke option. I'm all about light weight. But I'm 5'6" and weigh about 140lbs. So, there's my nickel. Go for it. Cheers

Hey Andy, You talk about holding the throttle constant and relating that to weight bias or contact patch, and later you mention holding the speed constant and relating that to contact patch. I'm feeling a little confused. Should I be thinking about the throttle position or my speed in relation to contact patch? I can hold the throttle constant and not be accelerating. Or I can hold the throttle constant and be accelerating. In my opinion, I need to relate contact patch to a condition of speed. Accel, decel, or constant. Don't you find that you need to have the throttle at least cracked a bit to achieve a 50/50 balance of weight bias? Or constant speed? In my opinion, coasting at zero throttle thru a flat turn is decelerating. And running wide. Not 50/50. How about you? In any case, I agree with your statements, scarabrae. You seem to have it sussed. Cheers.

EE-GADS!!!! $375USD and two sets a day...I don't remember things being that expensive (memory block) but maybe that explains why I'm still paying on five credit cards from last racing season..... Of course spending several months in New Zealand didnt help the credit card bill either... Seriously, the last BIG race i did was Laguna Seca World Superbike 98 125GP teaser class. I think I bought four sets of Dunlop slicks (2 soft, 2 super soft) in case it was cold...at special price of $180USD per set. Now I think other guys might have been paying more like $235 or there abouts, but i came home with two sets. After four days. Obviously 125gp tires are smaller hence cheaper. Different manufacturers here used to pay "contingency money" for running stickers. If you win, place or show...there's your discount or maybe free tires if you are winning. Same for oil, fuel, chain, bodywork, brake pads, etc. Racing in America is not quite the same sort of thing as it is over the pond tho... When i was considering doing the Euro Circuit with Rod Fee, Doug Carmichael et al, i was told you got paid if you qualified and started the race...start money I believe they called it. S**T! People in America would never believe that..but, maybe now that all us old..er folks paid the dues to bring up awareness and so many kids taking advantage of the dwindling stigma we had to deal with...just try walking into a pub dressed in leather around here when i was ..um...younger....things might change...but i doubt it. half the board of AMA was controlled by the big four manufacturers, cant imagine that's changed. If we could get thousands and thousands of spectators to come to the races maybe.... Now Ive found other things to risk my life and spend insane amounts of money on...like racing sailboats on the open ocean in a typhoon...or taking flying lessons... . But...I've had a hankerin' lately to 'turn a wheel in anger'. I know there are "qualifier tires" and tires made to last a single race, my guess is most guys in the states don't have access to that stuff unless they are on AMA National Circuit and even then...not everyone. But I have no firsthand info on that. Just nasty rumours about who gets special treatment. I would never say the word fix. I've just heard rumours... Maybe we should discuss a little import/export business.... Must be really cool to be so close to Euro tracks and Isle of Mann. Oh well, Merry Christmas...er...Happy Holidays.