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tweek

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Everything posted by tweek

  1. I've never ridden Barber's track so I've been doing a little homework before this coming weekend. Here are a few things that might help out: Videos: Track Maps: http://www.barbermotorsports.com/trackmaps.php Nothing replaces actually going there and riding, but you can at least arrive with some idea where the road is going. Also - arrive early or stay late so you can check out the museum. I plan to spend Friday afternoon checking the place out.
  2. bigdawg - agreed. However, if the physics say it can't be done - I'll let Stewy try it out first. If the math says its possible then I'm willing to work my way up to it. The sucksville about doing the math is that, at least here, we really aren't making a accurate model of what is going on in the real world. We're not factoring in the suspension, the fact that the surface isn't perfectly smooth, the atmosphere (wind), tires, the rider's body position, etc, etc. All we have is a very simply model that says such and such a lean angle going around such and such a radius of turn will need about this much speed in order to balance the forces. I'm doubting my buddies at MSR are going to let me take my measuring tape out to measure the radius of all the turns on the 1.3 miles track. Oh, and that track is on the side of a hill so what about the camber of the turn? What about the fact that one of the narliest turns is crowned right at the apex? Way too complex to model, at least for me. based on Racer's posts though I'll expect a thesis any minute now. At the end of the day I'm just killing time until the next track day or school. This helps my understanding which helps me a little bit when I jump on the bike, but at the end of the day - this is just for laughs.
  3. another point - reworking the formula and solving for r comes out something like: r = v*v/(G*tan(50)) so clearly according to the formula if you increase velocity (but nothing else) you increase radius. Now if somebody could figure out a way to make local adjustments to G we'd be in business.
  4. I really want this thread to die now....but..... I said the radius would increase if once leaned over you start feeding in more throttle. Seems reasonable. But one of the things brought up is what roll does the front wheel play while the bike is leaned over. So if I get ham fisted with the throttle and spin up the rear wheel the rear wheel will drift out on to a wider arc. What about the front wheel? Based on watching so really trick riding the front wheel stays on its line but with the rear wheel going out - the bike points more to the inside of the turn. I believe this is referred to as squaring off a turn and occasionally a highside. I really can't wait till next weekend. I'm going to drove you guys nuts. I really want to spend some quality time with the lean/slide bike so I can get this in the real world.
  5. I'm not really sure, but next Friday we can do some experiments with the lean bike and find out at least if Mr. Code will kindly turn his back and look somewhere else Just want to leave enough time to go check out Mr. Barber's museum and get some pictures.
  6. [All of my 'advanced' math is linear algebra and combinatorics - I can count bottle caps. Some how I missed out on all the good calculus classes, only got 1 & 2 - so bare with me] I'm not 100% sure why the radius increases w/ more velocity. However, I'm pretty sure more velocity (keep all other variables constant) won't decrease the radius. I'm guessing the radius increases b/c the lateral force exceeds the rear tire's ability to grip. However, that would mean that as the radius increased the lateral force decreased. Does the forumla support that? Factoring in things like friction though starts making the model more complicated than necassary. But I guess it's sort of a logic thing - if velocity has no baring on the turn radius why to race bikes have such big brakes? If velocity isn't a factor then Nicky Hayden would keep the same velocity through every turn and hold the bike on its red-line through out the whole race. But that isn't what happens. Or am I making a hash of things?
  7. Sorry about that - work intruded. I need to spend some quality time with my white board to grok what was done. But with the quick glance I gave it - Should have been able to get that myself. nothing more than highschool physics. Thank you. in general I don't think a super accurate model is needed to get to what I was after. simply - about 30mph is how fast you need to go in order to lean the bike over 50degrees. I've gone back and reread the relevant bits on TOW2. So the answer to my original question - lean angle == turn radius is false. the two variables are part of a larger system affected by velocity and weight. For instance - keeping the lean angle constant, and increase velocity. Radius increases. oh well. For practical applicaitons (we don't ride on skid pads - at least not until next year when DMG takes over AMA) we also have to consider how quickly you turn the bike. Keith goes on at length about this. Basically, the fastery you bring the bike to max lean angle the less lean angle you need. Which seems like fun feedback loop to have to deal with. IE - first pass through I lean the bike over slowly, scape my knee through the corner, finish off my latte and exit the turn. Next pass I'm in a hurry, using the same turn in point I slam the bike over like I'm Rossi and end up looking at at surprised corner worker so I have to either roll on more throttle or stand the bike back up. Third time I keep the same TP and still slam the bike over but this time I don't gone over as much. Next time same TP, same steering rate but more velocity. Knee scrapes, no surprised corner worker. anyway - I think this horse is dead. I get it and have the math in hand so I can think about it further. My big take away from this though is how critical the steering rate is in the real world. Next week we'll work on that.
  8. Have some free time so I'll bug you guys some more! Not sure where all this will go, I've not quite planned it. First, what should be a straight forward math/physics problem/simulation: Say you have a 200lbs rider with a 400lbs sport bike. The rider and the bike are on a giant flat cement skid pad. The rider is holding the bike in a constant radius turn that makes a circle with a 50' ft radius. How fast does the bike have to be moving in order for the rider to keep it at a 50degree lean angle? (I really would like to know the equation for this) The above problem I think is at the heart of all this. what will happen if the rider is going too slow? My gut feeling is that the bike will fall over just like a top that has lost its speed. However, now I have doubts about even that. If the rider is too slow and holding the bike at 50degrees of lean angle will that just cause the circle's radius to shrink? What is the relationship between speed, lean angle, and circle radius? I am simplifying things because we are not considering things like tire grip and surface friction. So for instance, if the rider, while holding the 50degree lean angle, tries to go too fast and force the bike to stay on the 50' radius then the tires will have to slip. Which tire slips first or will both let go together? what does this have to do with the 'real world'? Confidence. At least intellectually. If you KNOW that the bike can be leaned over to 50degrees and not fall over on you then you know how far you can lean the bike. knowing that then you can quick turn the bike that far and know that the bike won't fall down. Some people are blessed with the ability to just hop on the bike and feel their way to this knowledge. My youngest daughter is like that. I on the other hand have to eat the apple first and then practice, practice, practice and ask tons of questions. So there you have it. Anybody up for some physics calculating?
  9. Racer - you're right. I think I mentioned that I tend to over think things. 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. Happily I'll get to bug Coby about this stuff in person in just a few weeks and get all my answers questioned.
  10. racer - yeah. and I'm repeating myself b/c I'm trying to grok this and it aint easy for me. The thing that blew me away though was how much easier my new bike is when compared to my crufty old Tank. I love the ZX6e and its a great bike, but the 848 just crapped in its punch bowl as far as track days are concerned. I realize that the points you and others have made are correct, but for some reason I'm not quite getting it. I also know that touching your knee down is not necassary to going 'fast', in fact up to a certain point it is probably somewhat slower. However, I think what I'm trying to gain is the physical control and confidence over the bike such that I am freely able to choose when my knee touches. Having the confidence to lean the bike over that far (actually, as long as my legs are it isnt that far) should make developing the other skills easier. Or at least that is my working theory. Coby - the lean bike was broken last year when you guys visited Mid-Ohio in August so I didn't get to ride it. I arrive Friday morning sometime (don't have the plane ticket in front of me). I plan to go straight to the museum and then come over and watch my friend do his two day camp stuff. Sense I'll have all my gear in the back of the car maybe I can weasel my way on to the lean bike so we can have that out of the way. finally, maybe we can work out exactly what it is I need to do in Level 4 so that I can ride fast enough to give my new bike a good bit of excercise.
  11. It is amazing how a few more days on the track and a new bike can change perspective. Still don't quite have the answer in hand though. Yesterday (Monday) was my first time to take my Ducati 848 to the track. Usually I ride a 99 ZX6e. All I care to say it WOW! The brakes on the 848 certainly gave me the confidence to push it a little harder down the straights. The 848 is also a lot easier to move around on. Handing off I'm easily able to get my chest parallel to the tank where the tank's ridge is against my ribs. Even better was that I was able to get my knee down 3 times on my right side and once on my left. I've only gotten my left knee down on the ZX6e. I just don't trust it as much as I do the 848. Guess which bike is going on craigslist? So while I'm able to get myself off the bike and lean the bike enough to occasionally touch my knee down - I can't do it accurately or consistently. I'm not even sure what I did differently the times that I did touch. My goal is to be able to accurately and consistently get my knee down once I know where the track is going (ie I'm not looking to do this on a mountain pass). I'd like it to be as controlled as a NASA launch - 5-4-3-2-1- touch down! and then 3-2-1 lift off! (Without NASA's fondness for mixing up standard and metric and blowing things up). Anyway, what is it that I'm missing? At this point I'm easily in the middle of the intermediate pack. Maybe even moving up toward the front of them. But I know that I'm not anywhere close to using up all of the ZX6's potential. Won't even think about the 848's capabilities. So what are you guys thinking about, doing, looking at, (perhaps hearing & feeling too) as you go in to a turn that you absolutely know you are going to lean over far enough to drag bits? Does the speed matter? And before anybody says it - I'm signed up for CSS level 3 & 4 in May. So I'll get to bug Keith and crew all weekend about this stuff. But I plan to read ahead so I can get as much out of those two days as I can.
  12. First - prepare for the greastest drug ever created. the down side is you won't be able to get it off your mind after you've been out there on the track at speed. It has turned me in to a total junkie. Second - trust the school. Keith and his gang run a tight ship, it's like clock work and nothing gets screwed up. Just follow your coach's coaching and not only will you be safe as houses you'll go faster than you can imagine. oh - drink water and take the supplements. most of all - enjoy what is absolutely a great present.
  13. Well, the lovely Whitney just called and moved me up to the May 31st date so I best start working on my hitch hiking skills. See you guys (and gals) then. Almost like Christmas came early this year.
  14. If somebody drops out I'll find a way over there even if I have to hitch hike.
  15. thanks! Now kick a few people out of class so I can get off the May waiting list and come out and play! Kidding - I wouldnt want anybody to miss out on the greatness of CSS for any reason.
  16. This thread has been an excellent read (along w/ Racer and Ulysses bickering back and forth) and comes just in time. Specifically, I got started last August with CSS level 1 & 2 which was the first time I had been on a track on a bike, sense then I've done 10 to 12 track days. Initially I didn't bother handing off. I clamp on to the bike with my knees and lean my upper body. However, as I've picked up speed I've started to move more of my body in order to keep the bike more upright. During my past three track days I've actually started sticking my knee out and at my last track day even I actually touched once. But here is where it gets complicated - my throttle control isn't where it needs to be. Some of the grey beards around here looking at my tires say that I'm deaccelerating through most of the turn which is why I'm starting to hit hard bits again. It doesnt help that my track bike is ancient (99 ZX6e), but still. So my comment is: while you're busy trying to look like Troy and scrape off those knee pucks - keep your right wrist in mind.
  17. I know I'm asking way in advance, but..... Which hotel is *the* hotel for Barber? I was going to go in May/June but all you apes took up the spots so I'm going in August instead.
  18. First, Mr. De Puniet drives me nuts. I'm trying my damnest to root for Kawi but he keeps going off and dual sporting in the gravel traps and taking other riders with him. That isn't fast - it's dangerous. Glad Kawi have moved on to find new riders. Hopefully, Mr. West will figure out where he is supposed to grid up and win a few podiums this year. As for the front end sliding - funny, I'm rereading the books getting ready for another season and I just finished the section on throttle control.
  19. I'm doing level 3 & 4 in May. Think I'll have to do this next year instead of the 2 day camp. Sounds like a load of fun.
  20. Wooo hooo! -- See you guys in May at Barber. Can't wait.
  21. I weight 220lbs and the shock is setup for 250lbs so it is about right for me in full gear. The front end is stiff and you definately feel everything, but I like that. The 6e suspension from the factory is way soft. The difference between stock and what I have now is simply amazing. The bike's handling is super responive to inputs. Before, leaning over in a turn just felt vague and slow. Now its razor sharp and immediate. I so can't wait for Monday.
  22. not sure which new bike you are refering to..... the 99 ZX6e (new to me, but.....) is mostly for the track. I ride it on the street occasionally, but w/o mirrors I'm doing it less and less. the bike to be (probably a 08/09 ZX6R) will see some track time, but it won't be dedicated.
  23. Right now I have a 99 ZX6e. We just installed a Works shock on the rear, and 1Kg front springs w/ emulators. Monday (11/5) is a track day so we'll make whatever adjustments are needed then, but overall I doubt there will be much more to do to this bike after the shop finishes up. The biggest issue left will be tuning the engine so it runs perfectly. If there was a track nearby that CSS came to then I'd probably drag my bike out. But Barber is as close as CSS gets to my house and I think I'm going to indulge in being lazy. It's nice just packing bags, getting on a plane and not having to worry about things. Overall I'm pretty confident Keith and his gang will make me faster regardless of the bike I happen to be riding at the moment. Now if they'd only hurry up and post that 2008 schedule so I can make my plans......
  24. I'm planning on taking level 3 & 4 next year (waiting on the schedule.....). I am trying to decide whether I will bring my bike or rent the school's. I read somewhere that it is prefered that students bring their own bike for level 3 & 4. I'd like to better understand the reasoning for that. My bike is old (like Jurassic old) and just finished having its suspension upgraded and tuned (works shock in back, new springs and emulators in front) so it is tuned about as well as it can be. Plus, I plan to purchase a new bike (or at least from the Holocene). So all the human to bike interfacing stuff has to transfer from my 99 ZX6e to whatever 08/09 model I buy (likely to be a ZX6R). The real reason I'm asking is b/c I'm lazy. If it all works out right I plan to watch the AMA race at Barber on Sunday and then do school on Monday and Tuesday. If I can just fly out and rent a car it's a lot easier (throw gear in one bag, underwear & tooth brush in the other and I'm off). But if there is really a compelling reason to drag my bike out I'll dig up a trailer and do it. Thanks.
  25. when will the 2008 schedule be posted? I need to know when you guys will be at Barber next year so I can make plans. Need more schooling! Need to go faster!
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