racer

You're scaring my, Racer. The things you're mentioning are either insignificant (not trying to start anything) or not complete. Let me simply clarify this, and I'm sorry if it seems disorganized, but I just got off work, and am typing off the top of my head. I just explained this to a new diabetic a couple hours ago. Sugar in the blood is useless without insulin. The body uses glucose in the cells as energy. In order for the glucose to get into the cells, they have to bind with insulin. That's why some diabetics have to inject themselves with insulin. They're body's don't produce insulin, so they help it out. The other one's, the "roller coaster" types are almost always going to be obese people who DID beat their body up with tons of junk, and inevitably develop insulin immunity, but this is after years and years of abuse, and tons and tons of ###### food. Most people who go to the track aren't the people who are going to have to worry about this sort of thing. Well..... excluding the 300 lb guy who tools around our beginner group on the 450 dirtbike. He's fat, and I'm SURE lives a sedentary lifestyle outside those 8 hours 4-5 times a year. A couple of sports drinks aren't going to hurt someone as active as a trackday rider. I'm not sure what your point is. A bag of white sugar is a good diet for the racetrack? Your post seems to support my point. Repeated simple carb (sugar) intake puts your blood sugar on a rolllercoaster and overworks the pancreas. Period. Whether for an athlete or your grandma, this is bad. Period. Do I think a few sports drinks at a track day will cause someone to contract diabetes. No. I didn't say it would. However, that doesn't mean it is a good idea to take in a lot of simple sugar or that sugar heavy drinks are good for trackday riding either. I go for complex carbs. They breakdown slower and last longer giving a more even and continuous supply of energy (sugar to the blood) over a relatively long period of time. Again, I'm not a scientist and I only know what I read in peer reviewed journals and such and, according to these sources, this is the current state of the art of athletic science and nutrition today. r

This statement couldn't be more wrong. Yes, I corrected myself above. Perhaps you missed it. As for K being insignificant... I'm not a medical doctor or even a health professional. And I only know what I was taught in mainstream university 25 years ago and what was published in JAMA in the 1990's when I was researching these things for my own benefit. And no I'm not going to search for footnotes now. I'd suggest that folks who are concerned about this topic should do their own research and that the best data is probably not going to be found on a motorcycle racing school website in any case. That isn't to say good data can't be found here, merely that unless someone wants to post their qualifications, CV, and relevant peer reviewed research, well... you might take it with a... erm... grain of salt? <g> r

That looks like the unit my friends at the firehouse use to look inside walls of burning buildings. I believe there is standard tire tester with a needle like probe to stick in the tread. I've never owned one. My tire warmers had a thermostat. I set that, checked pressures and went by the look and feel of the compound. Worked for me...

Hello everyone, Re: the "cut and paste" article... First: I don't know what source that is from, but, please, consider that the bikes and tires being discussed are "vintage" and bias ply rubber, not modern machines with racing radials. When it comes to modern radials, there is no blanket specific pressure rise "rule of thumb". Even with older style bias ply rubber, you need to use a percentage based pressure rise, ie. back in the day, 15% was the rule of thumb which works out to 4.5 psi for 30 psi starting cold pressure. Unfortunately, with modern radials, that rule of thumb is not really reliable. With a lack of any other info, a minimum 10% rise is probably a good place to start to develop your own data. However, at the end of the day, the only truly accurate way to measure tire temperature is with a temperature probe... (thermometer). Contact the tire company you are using for the precise temperature range you are looking for. In general, I think something around 170-180 degrees Fahrenheit was a good range for the tires I used ten years ago. But things have surely changed since the last time I raced. Generally speaking, a good trackside tire vendor should have relatively reliable data for the tire brand/model and weather conditions for the tracks they work... assuming they are working at the track and not some on-line vendor or whatever. Bottom line, contact your tire company rep and get a good temp probe. In the meantime, I would ask Will "Balistic" here at CSS as he raced a ZX6. Don't know what tire he used, I would guess Dunlop. r

Yes, definitely, BOTH Sodium AND Potassium are needed by the body and depleted by exercise and sweating. What I should have said is that most of these sports drinks seem to only have Sodium and simple carbs ... read SUGAR... that absorbs and breaks down quickly for a short rush and then crash as the body (pancreas) secretes insulin to keep the blood sugar level. So then your body ends up on a roller coaster ride of sugar and insulin which is really bad for your body and pancreas, too. The pancreas also makes other stuff your body needs, hormones and glucagen, etc. I'm told that this sort of roller coaster ride is hard on the pancreas and what wears the pancreas out and causes certain types of diabetes, too. Anyway, I didn't know about cell salts or bio-plasma. And the blood pressure/sodium connection was drummed into me as common knowledge. I had no idea it was disputed. Thanks for that info. I've also read that most headaches and pain in general can be attributed to or made worse just by general dehydration. I'm told that is what a hangover is as alcohol is a diuretic that forces water out of your body. I can say that drinking lots of water can prevent and help cure a hangover better than aspirin. Anyway, good to know you guys are on top of it. Cheers, b

Thank you, Kristi. And yamfz. It's nice to know my efforts are appreciated and that I've been some help to someone.

One of my favorite riders is/was Pierfrancesco Chili. He was usually stuck on B team machinery and had to work twice as hard to prove himself. And he is a super nice guy. Really cool. He was my wife's favorite rider as well and she was really excited to meet him at Laguna Seca in July 1998 when we raced the 125 support race for the world SBK weekend. PC was totally cool and happy to hang out and chat with us as long as we wanted. She was bubbling for a week afterward and so cute when she cheered for him... CHILI-I-I-I-I !!!! (lol) And there's another Italian rider (his name escapes me at the moment!) who was retired from full time racing but working as test rider for Aprilia the last I heard... some years ago. He would fill in once in a while when an Aprilia rider was hurt. The common denominator is they were both over forty years old and still competitive on the world level ... working twice as hard riding 'B' team machinery. They really inspire me. My first hero was Wayne Rainey. He inspires me too.

You are right Racer it is a crazy tight odd little track, that is my local track, infact it is the only track within 100s of miles of me so where I do most of my trackdays, I am planning on traveling further afield next year for track days though! Here is a list of Leons results for the year Thruxton: 5th, 4th Oulton Park: 3rd, 3rd Brands Hatch GP: 5th, 3rd Donington Park: 5th, 4th Snetterton: 1st, 2nd Mallory Park: DNF, 8th Oulton Park: DNF, DNF Knockhill: 5th, 8th Cadwell Park: 4th, 4th Croft: 1st, 5th Knockhill can be a tough track, the guys are lapping in under 50 seconds and with only 1 left hand turn the tyres take some abuse on the right hand side but as you say, I guess he must have been having an off week that week! I meant to put "off week" in quotes to point to the fact that Leon was coming back from DNF's. Not unusual to hold back in that situation. I'm glad to see he is back on form again! Anyway, one of my customers is a car racer whose home track is Knockhill and he told me it's pretty intense and also subject to unique weather being down in a valley. (It was raining the day I watched the BSB races.) Personally, I like tight tracks for smaller bikes and the turn one two combo reminds me of Phillip Island but shorter and steeper. You see the same sort of overtaking moves: outbraking into turn one, running wide and having the inside line to block the entry to turn two. I noticed lots of that going on!

In hindsight, "slippery" probably wasn't the best choice of words to describe the "less than warm" Qualifiers. The point would be better stated as: potentially less grip when cold than a tire designed to run at lower temps. And, I'm only going by what our tire rep and customers tell us. Also, if you look at the Dunlop tire usage chart, they do specify the Qualifier for track use and/or street use. It's just that the ads call it a "street tire that offers race track grip". Which is true, but, only half the story. They need to be really warm to offer their best grip. And that grip is still not as sticky as a full on race compound. I think they are probably fine for riding on the street at less than optimum temperature. I don't think they are going to be "slippery". (Sorry if I misled anyone with that. My bad. ) As for being able to slide the tire... I agree with Keith. However, my opinion is that consistency and predictability is most important when learning to slide. FWIW, a tire that needs to be warmed up first, like the Q, might not be as consistent over a varied or broad range of riding and temperature conditions. If that makes sense? PS - For the record, I have always run Dunlops. They have always been my favorite tire brand. Right back to the bias ply race tires I (and CSS!) used to run before radials were invented.

ROFL = Rolling On Floor Laughing LMAO = Laughing My A$$ Off ROFLMAO = Rolling On Floor Laughing My A$$ Off

I suggest taking the school before doing a track day if you can wait. That way you will be better prepared (skills and experience) and confident for the track day. You will know how to make better use of your time there and you will get more out of the money you spend on it. PS - Cool bike!

Sodium is OK, but, Potassium is better. Sodium raises your blood pressure. Bananas are a good natural source for Potassium. Some "sports drinks" offer potassium, too. I think Powerade has more potassium and complex carbohydrates and is better than Gatorade which has more Sodium and simple sugar. Also, some of the vitamin waters, too. Read the labels. Also, I suggest diluting Powerade or Gatorade 50% with water. Half and half. ETA: Oops. I see Thor already mentioned Potassium and bananas. If bananas upset your stomach, I suggest trying Powerade or supplements.

I caught the BSB races at Knockhill this year. Leon had an off week, I guess. Crazy tight, odd little track, though. Made me feel better about some of the tracks we had to ride at Nationals back in the states.

Thank you for asking that question, Will. I said that gravity and what it creates (friction) is responsible for the tire sticking to the pavement. And I said I think that momentum is the source of potential energy tapped by the geometry of the "twist induced into the steering head" (as you said) for horizontal (wrt the bike) force to induce roll and a quick turn/flick rather than merely a fall due to gravity. I also said that gravity adds a vertical component of force to the leaning, but, that, by definition, it doesn't account for much motion above 45 degrees of lean. In any case, I think Bobby pretty much closed the issue of gravity vs momentum by pointing to the ability to flick the bike back up. I hope that answers your question. I don't think I will have time to continue my simple, plain English treatment of the physics where I left off with the narrow "single track" and the different types of momentum until late Wednesday at the earliest. Have a great weekend! Go Steelers! BH PS - The title under your photo at left still says "Riding Coach". Are you going to change it to "Mechanic"?

It still surprises me that you guys get tires that we never get! C The Dunlop Roadsmarts have been available here in the US for the last year. Tucker Rocky and Parts Unlimited both carry them, hence, you can order or purchase them at any motorcycle shop. That said... Although there are differences in carcass construction, the major critical difference between the Qualifier and the Roadsmart is more silica in the Roadsmart compound. A higher amount of silica makes a compound less reactive to temperature, hence, the Roadsmart, with a compound designed to operate at lower temperatures, is the better choice for a street tire as typical street riding doesn't create enough heat to bring the Qualifiers up to full operating temperature. This is why we hear so many complaints about the Qualifiers at our dealership. Guys ride around on them, find them to be slippery with less grip riding around town, and then discover that they only last half as long as other road tires. @*%$*! Unfortunately, retailers, the people who sell the tires, typically don't know enough about them and Dunlop hasn't really marketed them very well... as evidenced by Cobie's last posts. His company sells Dunlop Qualifiers and he doesn't even know Roadsmarts are available here. And neither did I until a few months ago and only because I sell them for a living. EVEN MY MANAGER thought that Qualifiers were not really for the track until the rep explained the differences to him. Bottom line, the marketing of the Qualifier as a street tire with "race track grip" taps right into the average street rider's lack of knowledge and experience to sell more tires. I hate to be cynical, but, that is the only reason I can think of for it. The Qualifiers wear out faster and Dunlop will... er... IS selling more tires this way than they would if my customers were buying Roadsmarts. IMO, if you aren't riding track days or canyon riding, buy the Roadsmarts. You will get better performance than you will riding around town on half-warmed Qualifiers that wear out twice as fast. racer

You know, I think you might really be onto something here, Bobby. Not only about the time it takes to lean the bike, but, also the difference at different road speeds. This is what I was thinking about today while communing with a 600RR and meditating on Will's leverage angles. The amount of force and leverage it takes to turn the front wheel increases greatly with speed. Partly due to the increase in resistance of gyroscopic forces, and, I think maybe partly due to resistance of the caster or trailing geometry. I wonder if resistance due to trailing geometry also increases with speed.

Um... okay. What do you think causes friction at the contact patch of a motorcycle driving in a straight line, Jay? Cool. You are the first person to say you understood my analogy. Thanks. So, what other force(s) do you think are involved? Erm... really? In what other direction does gravity act here on planet Earth? With all due respect, Jay, I think you might be mixing gravity up with some other force(s). Here is a link to an excellent online website for Physics and Kinematics (presented in plain English) that I found very helpful. http://www.glenbrook.k12.il.us/gbssci/Phys/Class/BBoard.html

Ah, wheeltrack. Thanks. I assumed that the word "narrow" would provide a clue in that context. Agreed. Discussion, not argument. And I tend to agree with your conclusion. My personal belief is that this is because the bike is rotating. Not falling. So, there is a horizontal component of motion (or vector) as well as vertical. Hence, we cannot merely consider the vertical force, gravity, alone. I'm actually at work and sneaking off to read this. I have to bolt before my boss catches me being bad.

I think we agree on about 85% of what you said. However, I will need more time to study the points of your theory I am not clear on and craft a skillful interrogative to clarify the other 15% if necessary. I am off to bed now to rest up for 40 hours of work in the next 3 days. Cheers

OK... Will, Cobie, Jay, and anyone else... I think it is safe to assume that pretty much everyone here is familiar with the experience I described above and is with me so far. So, I think the next step is to agree or understand why that happens. Here comes the science. Most folks have probably heard of Issac Newton, if not his Three Laws of Motion. In any case, Newton's First Law defines a property of motion called "inertia". In a nutshell, the first law defines inertia as the tendency for a body at rest to remain at rest or a body in uniform motion to remain in uniform motion until acted upon by an outside or unbalanced force. ("Uniform", in this case, would indicate a consistent type of motion, like a straight line.) So, driving in a straight line, if you turn the steering wheel of your car (imparting an outside force), the mass of you, your passenger and the car itself will try to keep going in a straight line. We "force" the car to change direction, but, everything inside, and even the car itself, resists that change and tries to keep going straight. Taking it to the next step, if we are driving a relatively taller vehicle, like a van or a truck (especially loaded up high with cargo), that "top heavy" vehicle has a higher "center of gravity" and will have a tendency to lean more or even to tip over if we steer it hard enough. As I know you are also a professional truck driver, Will (as well as a mechanic), I'm betting you are familiar with this concept, too. This concept would also apply to a vehicle that is more narrow, rather than simply taller, as it is the relationship or ratio of height (specifically of center of gravity) to width that defines the inherent stability of any vehicle (or body) in motion. So, if your vehicle is taller and/or has a more narrow wheelbase, it will be less stable. Sports cars have a relatively wide wheel base combined with a low center of gravity for increased stability. OK... last step. Now, here is where it gets a little tricky... because of gravity (and the sticky nature of rubber), there is "friction" created between the tires and the road. Friction is what causes the wheels to stick to the road and allows the vehicle to go in the direction you steer it. And, because the wheels stick when you turn the steering wheel, the energy of the vehicle trying to go straight causes it to "roll" or lean sideways (rather than slide). BUT, to be very clear, it is the FRICTION that allows that to happen. Even without gravity, if the wheels were sticking to the road because of say magnetism, the car/vehicle would still lean toward the outside when steered into a corner. Same thing if your butt was glued to the seat with superglue rather then gravity. Your body in the car would still lean. The point is that it is FRICTION that creates a fulcrum and lever (or moment arm) acted upon by the force of inertia/momentum that allows or causes the leaning, NOT gravity sucking your body down. Finally... Ultimately, the extreme example of a vehicle with the most narrow wheelbase is a motorcycle! I will stop here as it seems a good place to break and I have spent most of the afternoon of my day off working on this and I need to get some other stuff done. I hope those who were made drowsy will dedicate at least a little bit of time and effort to try to follow along and come up with specific questions if there is something that isn't clear. Thanks, racer PS - pursuant to the term "momentum" and "moment arm", I should define a couple more terms. A body in motion has "momentum". Momentum is essentially a way to measure inertia or tendency for a body to remain in motion in terms of potential energy by measuring and multiplying the mass of the body and its velocity. In other words, the heavier and faster your vehicle, the more momentum it has and the greater its tendency to remain in motion, and, the more force over time... or energy... it takes to stop it. So, in practical terms, it takes more force and/or more time to stop a heavy truck than a small car, ie. more brakes and/or greater stopping distance. There are basically two types of momentum. "Linear" momentum which I described above, and, "angular" momentum. Linear momentum is a property of a body moving in a straight "line", hence, the word linear. Angular momentum is property of a body moving in a circular fahion or rotating/pivoting. I don't know if it is proper to call a moment arm a lever, or the point about which it rotates a fulcrum. However, the swingarm on a motorcycle is a good example of an arm that rotates around an axis at the swingarm pivot. I will do some more research to find out what is proper so I don't steer anyone in the wrong direction by posting bad data.

OK. I can handle that. It would help me if you could say more about where I lost you. For instance, I presented a "plain English" example/analogy of a four-wheeled vehicle rolling opposite to the direction of the turn when steered into a corner, ie. turn left and your passenger is pushed into the door and the vehicle tilts that way, too. Are you familiar with this experience? (I assume you are, but, better to be certain everyone is on the same page.) PS - I live in the US and our steering wheels are on the left side of the car as we drive on the right side of the road. Hence, drivers in countries that drive on the left side of the road will steer right to push their front seat passengers up against the door.

Excuse me? What? Your response is to characterize and blame my writing style to allege some inability on your part to grasp the simple and clearly demonstrable concept of lateral G force (turn the wheel of your car and your weight goes sideways)? And then to direct an unsupported ad hominem attack and accusation of dishonesty and deception at my person while ignoring the points and ideas I presented? "Hey, look over there at that 'pedantic ramble' (yawn). It's so intentionally tricky and twisted that it's making me drowsy. I'm a wheelie expert and a coach, and I suggest everyone ignore it. All science can tell us is the 'why' anyway." Are you kidding me? Misdirection and subterfuge? Who? Let's be clear... you said you "love this topic". And then you opened the door and invited discussion of "esoteric" scientific concepts with your comments re: gyroscopic precession and gravity. The whole thing was your bloody idea, mate! I naturally assumed you were honestly representing yourself and your interests. My bad. Then again, perhaps I misunderstood you and the topic you love is merely gyroscopic precession not being responsible for turning a bike... because you believe you have the answer to that. Just one question... If you aren't interested in science or learning (and can't be bothered to ask for clarification of a specific point you didn't get), why bother reading a thread that is dedicated to science? Much less say that you are interested and then turn around and post negative, derogatory and troll-like remarks mocking the thread topic and posters who disagree with you? What's up with that? Whatever. Have a better one. racer PS - For the record, it was not my intention to label you (or anyone) in particular as a "layman". Nor do I consider the term any sort of an insult. However, I do consider myself to be a layman, albeit one who studies and enjoys learning something new. If you assumed I was trying to put down (or talk down to) people by using that term if they didn't agree with me, then, I apologize for the misunderstanding. That wasn't my intention at all. My only intention was (and still is) to learn and to help other people in whatever way I can. That said, it just happens that this is my favorite topic and I do love discussing it. I'm not trying to "win" anything or even to be "right". I'm happy to be wrong. I love being wrong. Being wrong is the beginning of all learning. I do not believe that I know everything or that mine is the final word and I would love to learn something new today. Hence, why I qualified all of my ideas in this thread with "in my opinion" (IMO) or "I think" or "I believe", etc. I'm not that guy who said, "it seems" is a nice way of saying "you are wrong". I was sincerely hoping for some genuine, on-topic thoughts or ideas from anyone who is actually interested in this subject... as I indicated at the end of my first post.

Pardon me for replying to the post you addressed to Andy, but, for what it is worth... The under 21 British/Kiwi champ I tuned for in New Zealand rode a 600 in the World Supersport race at Brands Hatch a few weeks ago and has been racing a 600 "over there" for a couple of years now. I would guess that UK racing organization rules differ from the laws governing public roads and licensing. Unless of course he lied about his age and I just got him busted... r

Yes, Jim. Someone once told me that people who feel small and weak like to knock other people down because it makes them feel big and strong. Do you have any thoughts related to the thread topic? racer