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Jaybird180

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Everything posted by Jaybird180

  1. Hi all- Looking for opinions and options. In prepping my 5yo son's CRF50 for Supermoto, I discovered that the front fork is kinked just above the axle. It's pushed toward the engine a few mm, reducing trail. For dirt he's using the stock 10"/10" knobby tires and supermoto, using DOT treaded 10/10" size tires as well. His racing class requires OEM suspension and I've found the part numbers to order the replacement. I'm not sure if the handling change will be ONE MORE new thing that he'll have to contend with his first time out, or if as a 5yo he won't notice, won't care and will carry on bent or straight. I'm theorizing with the way they're bent now it gives added caster effect and is HELPING the bike steer after relaxing his countersteer input. I think it's wise to replace it but I'm wondering if we can instead save the $150 plus labor time and wait a season when he may be able to graduate to a class that allows aftermarket components. Thoughts?
  2. Jaybird180

    Can we do it again?

    Thank you. I still have a ways to go though I've made some good progress. Of the tracks I've ridden, ViR-N happens to be my favorite.
  3. Last year for my birthday, I redid L1 and the following day L2. I then turned around 2 weeks later and did L3, followed by L4. This year, again for my birthday on the same track I did L4 again. I rode the BMW S1000RR and had a blast! I didn't take lap times, but I could easily perceive my pace was quicker, smoother and safer since the last time I was at the circuit. I took a couple wins with me in that I realized at the consulting table with my peers that I went through the day and not once had a pucker moment. I had control over myself and the bike, even during the time when I blew my TP for T7. My other win was that I completed the day without the nagging of back pain that has come up over the years. I was able to use many of the L3 skills that I picked up and I also realized some areas where I can expand my new capabilities into and remove some old limitations. I can also say that I've had the pleasure of winding the S1000RR to WOT on the front and back straights. Maybe in the soon future, I'll be able to hold it there!
  4. Jaybird180

    best ergonomic mods?

    Many people buy a bike that's just wrong for them from the beginning. This is often the new rider who buys based on looks, buddies or moto-journaists' opinion. They live with the difficulty not knowing what they're missing. Sadly, many don't seek to modify what they have. Case in point is that you'll find many suspension settings left at the positions as delivered. On bikes above entry level you'll get adjustable hand and foot controls. I've kept aftermarket rear sets on my bikes; on my previous bike I needed a higher position. My current bike got them because I needed GP shift (is that an ergo mod?) and that was the only way I knew how to do it (found out about an aftermarket part later), but the stock position felt more comfortable, albeit with a slightly inferior lock on the tank. I put Apex bar risers on my bike during it's winter makeover. I've only ridden it twice in the new configuration, but it's more suitable to my body dimensions. Still needs a little tweaking though. I tend to like Stomgrips also. Unfortunately, my heat gun caught fire as I was preparing to add my newest set, so I didn't install them yet. Are mirrors an ergonomic item? I have a love/hate relationship with them- can't find a set that satisfies. I've had exactly ONE set that I liked but I seem DRAWN like a moth to a flame to buying something other than that brand...then I get disappointed and just resign to live with it until I break or scratch them, then I repeat the process. I've considered larger hand grips because...I've got big hands. And I wanted something more "cushiony". I think I"m good with the new ones I put on with the Apex set. I'll eventually get around to changing the windscreen. I think I need something with more wind protection. And I think the bike will look better with a tinted windscreen. I previously had an expensive European brand on it and I didn't get anything but it's good looks. I may have to go with an American brand that's more functional.
  5. Jaybird180

    Can Weight Shift Theory be debunked?

    I have some concerns about the discussions on "weight shift" theory. Albeit not telling the entire story, by summarily dismissing it sans a thorough review or questioning of their effect on the motion or change of motion on a motorcycle we could find ourselves lulled into a mindset similar to religious cultism. Is that healthy? It can be readily observed that if a rider moves his/her body to one side of the seat that the bike tends to lean (and change vector) and the rider has to compensate for such tendencies. It is possible to explain it away that the rider is making an unintentioned bar input, however the experience of riding with a pillion (passenger) would seem to betray that logic and provide a rationale that something else is occurring now that we have an asymmetrical weight distribution about the longitudinal axis. Is it possible to exert a force (weight) at a lever point away from the center of rotation and have a predictable outcome? A discussion on Gyroscopic Precession may be able to provide some clues
  6. When I talked with the Office staff, they made a point to remind me that there was another bike available other than the S1000RR for student rental, albeit in short supply. Can someone please remind me which model that is? Thanks
  7. Jaybird180

    Riding a School Bike

    Just talked with the office. It's the F800R.
  8. Jaybird180

    How Much Weight On The Seat?

    Makes it difficult for the front tire to follow the contour of the road.
  9. Jaybird180

    Can Weight Shift Theory be debunked?

    Thanks @Hotfoot and @Lnewqban for allowing me to work through this. I realized after re-reading this and a few other threads, thinking and letting it all sink in that I had been conflating separate movements of the bike. So I'll wrap it up thusly and perhaps bring this thread to a close. I've been thinking about this new chapter (I could almost swear it wasn't in my book before- LoL) and it seems that there's a jewel in there about the bike steering about the rear wheel (once leaned over). I realized that I'd been conflating the concept of a longitudinal rolling motion (leaning) the bike and the result of changing the bikes directional vector (turning). We can do all types of things to try to get the bike to follow a corner, but ultimately it's the result of the smaller circular circumference of the rear tire that makes the nose of the bike point in the direction with the lean, just like a coin standing on it's edge rolling in a circle. If this is true, the act of leaning and turning are 2 separate behaviors and are about different planes of motion. The leaning would be a roll about the longitudinal axis and turning would be a lateral movement or yawing motion about what is often referred to as Z- Axis. But these are still 2 separate changes of state of motion. I apologize if I caused anyone distress (other than myself). Eventually...I suppose, I'll figure the Motorcycle Theory of Everything (MToE).
  10. This past weekend I took my children out riding to our practice field. As "luck" would have it, only 1 of the 3 bikes wanted to play so my daughter after doing the first set of exercises I had for her allowed her little brother ride her CRF110. He had to get on his tip-toes but he was fine once he got it under power. Later the day, I was able to get his CRF50 started and I gave him some exercises to do on his bike. The last exercise I gave him for the day was a high speed run from one end of the football field around the goalposts and back around the other one. At a certain point, he began to get the idea of rolling on the gas through the turn! SUCCESS!!! I decided to jump on my daughter's bike to try to follow him. About midfield he began to pull away ever so slightly. The race was on! Because he was using only a single gear (3rd I think), I was able to get the bike slowed, downshifted, turned around the pole and back into the power in a lower gear before he was able to get his bike pointed toward the next goalpost with his VERY WIDE turns. I tried the experiment several times in various gears and I noticed the marked willingness of the bike to whip around the pole at small radiuses the lower the gearing. I also noticed that I was able to hold more throttle under control with a tight turn the lower the gear as well. Most of the time, he was able to hold enough cornerspeed that he was able to beat me back to 1/4 field and then he'd pull away very slightly again. It wasn't as lopsided a race as one would think. Many times we were side-by-side and hard on the gas. That was fun! At any rate...I'm wondering if there's a corollary on streetbikes with turn radius and gearing. Although I can't imagine needing to whip a streebike around a pole is there a practical way where I can experiment with this idea? I'm wondering if turn radius isn't only speed and bar pressure but there may be a gearing component as well. Next question: I'm looking for suggestions on teaching a 5-yo how to shift gears.
  11. Jaybird180

    Experiments with Shifting Gears and Turn Radius

    Clicked on the Stoner book and tried to find it in print version. Not available until Nov 2018!!!!
  12. Jaybird180

    Can Weight Shift Theory be debunked?

    With effective leverage only basically parallel with the road and feet in an awkward (forward) position, this guy can describe to you pretty readily what makes his bike change direction This guy however, with his bodyweight over the steering stem may have a different perspective on what makes the bike change direction When I was at the school last year, Dylan explained in a way that I thought was brilliant (for me at least) what Keith actually described but didn't use the same words in TOTW. Keith used the word "countersteer" and then described the action of the front wheel tracking the trajectory of the turn. Dylan used the words, "countersteer" and "prosteer" in the same sentence and I had an "Aha! moment". A read through some writings dismisses as negligible any effect of bodyweight on the influence of steering. I posit that there are too many riders doing things with their weight on the bike to dismiss it and I think some of the absolutism may be obscuring the effects we have on the ability to steer a motorcycle through different intentional means. The reason I started this thread was because I didn't want to muddy another thread where I saw glimpses of the poster perhaps getting some traction in this vein until the thread got derailed and rather than reopen a can of worms, I settled on a cleaner path. As anecdotal proof of combined effort, (that's often cited) Dani Pedrosa is known for using the Hook Turn technique at corner entry and throughout the remainder of the turn. He uses it in combination with his steering input to get the desired result. Being a school, I understand (and support) clearly the many reasons why it would be desirable to teach and emphasize countersteering then (relaxing input and) prosteering (by the bike's geometry) as a primary means of control. I hope that my intentions are now made clear.
  13. Jaybird180

    Development

    @faffi- Did you find what you were looking for?
  14. Jaybird180

    Help - How to learn/start using knee sliders??

    You are correct. Expectations dispel surprises!
  15. Jaybird180

    Can Weight Shift Theory be debunked?

    Grab a folding chair and sit backwards so you have somewhere to put your feet. The mass of the system equals yourself and the chair. Scoot over far enough and the chair tips. I’m willing to ponder that a motorcycle behaves similarly, even with those black gyroscopes spinning.
  16. Jaybird180

    Help - How to learn/start using knee sliders??

    No “advice” but here’s a little story from my experience: First time my knee came down was on a relatively tight and track- ViR Patriot about 2007. It was my last session of the day and I’d been talking with the guy pitted next to me and we thought that the track might have been too slow to get knee down. So we dismissed the notion. I was doing well, hitting my marks and in T3 (after the eases) I felt something brush my thigh. About a half lap, I realized it was the ground. I decided I’d better stick my knee out instead of tucking into the bodywork. Next lap on T3 I felt it graze the slider and I realized that just a bit more speed and it would probably happen. Grazed the slider again on next lap but again added more speed and it came solidly down. I began to look for and expect it on subsequent laps and began to understand why people refer to it as a lean angle gauge. It also became a point of timing for me that I could roll on the gas.
  17. Jaybird180

    Experiments with Shifting Gears and Turn Radius

    Perhaps we should have been discussing this instead. Only corollary that I could think of would be Garry McCoy’s sliding style of cornering, where he’d light up the rear, swinging the thing around the steering head. Caught a lot of flak until he won a GP race like that AND it was found that the tire was no worse for wear as only the top surface was heating up.
  18. Jaybird180

    Experiments with Shifting Gears and Turn Radius

    Thank you. No problems here.
  19. Jaybird180

    Experiments with Shifting Gears and Turn Radius

    I perceived that you felt a need to clarify for my sake- that I missed something in translation. Did I misunderstand that you thought I misunderstood? (LoL)
  20. Jaybird180

    Experiments with Shifting Gears and Turn Radius

    Wouldn’t the changes in leverage be experienced at the power plant end of the system? If traveling at any given speed in the 1st gear does the road, tire, wheel, sprocket, chain or countershaft know the difference between doing the same speed in 4th gear? I haven’t seen enough to be convinced that those forces are different, save for the power pulses (maybe); the same amount of WORK is being performed despite the advantages of leverage.
  21. Jaybird180

    Can Weight Shift Theory be debunked?

    Yes. Hang off to one side and the bike rolls (per your diagram above).
  22. Jaybird180

    Experiments with Shifting Gears and Turn Radius

    Why is that?
  23. Jaybird180

    Experiments with Shifting Gears and Turn Radius

    Probably that your entry speed is too low. I may have given the wrong impression and I thank you for pulling on me. I do recall shutting off the gas on entry and at a point during the turn getting back into the gas. I confess to being greedy with it however even though I was trying to teach my children to be smooth with it...I was trying to catch my son and the power-weight ratio didn't help much, but this experience forced me to stalk him for several "laps" up/down the field until I could make a safe pass up the inside, knowing he'd go wide. [EDIT: on further thought, I may have to look it up to know what it means to feel a need to use throttle on entry. Any hints on where to look?] Not sure if I understand what you perceive as a communication lag. This confirms my suspicion.
  24. Jaybird180

    Experiments with Shifting Gears and Turn Radius

    There are some proponents of the idea of having a little bit of gas on at the steering input. I think it's possible that riding "little" (relative to the rider) dirtbikes could be a case for that as a technique. Certainly it's easier to manage rear wheel traction in a lower gear when using this technique. On a road bike I'm hard pressed to think of how using a lower gear could be exploited. We are often more concerned with getting corner exit drive then making a tight turn...only case coming to mind where it could be useful would be Turn2 at NCBike. It's a right handed DR and nearly blends into T1 as if it's a double apex with the DR at the end, then there's a short chute downhill to T3 which is a left. One could intentionally backshift to get the extra maneuverability for T2, accept the penalty of being at the top of the rev range at the T2 exit and immediately upshift to the next gear prior to T3 entry point.
  25. Jaybird180

    Experiments with Shifting Gears and Turn Radius

    This is the context in which I used the word Stability Stability sta-bil-i-ty [stuh-bil-i-tee] noun, plural stabilities. 1. the state or quality of being stable. 2. firmness in position. 3. continuance without change; permanence. 4. Chemistry. resistance or the degree of resistance to chemical change or disintegration. 5. resistance to change, especially sudden change or deterioration: (The stability of the economy encourages investment.) 6. steadfastness; constancy, as of character or purpose: (The job calls for a great deal of emotional stability.) 7. Aeronautics. the ability of an aircraft to return to its original flying position when abruptly displaced. Source: Dictionary.com
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