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  1. Today
  2. Steer for the Rear - Ch13 of TOTWII

    Thanks for the suggestion to re-read some material. I'd come to that same conclusion as I began thinking this through on my way to work this morning. I do need to talk through some things as I read and also some thoughts: In Ch 2, the section on throttle control, one of the margin comments mentions that it's possible to get on the gas too early and cause the bike to run wide. In light of my new understanding of what the rear does in a corner, in that it's the dissimilar circle size on the side of the rear tire that causes the bike to turn I now ask :does the (greedy) application of throttle really cause a bike to run wide while leaned over? We already have observed that we can lift the front with throttle and the bike will remain as sure as if on rails. Ch 2 also give the reason for the idea behind the 60/40 and that it's based on a comparative measurement of footprint, nothing more. 0.1-0.2g of throttle is what's needed to maintain that relative contact patch. But since we now understand that size of contact patch isn't the determining factor in available traction should maintenance of footprint still be a Primary concern as requested by Ch2? I'd like to make a note here: I'm not advancing an idea of "whacking" open the gas, nor am I saying that a smooth roll-on isn't the right thing to do. I am saying that perhaps we needn't be as gentle with the throttle as I previously thought. If this is really the case, then perhaps I opened a door for more available attention for other things. I hope I'm not opening the door to more highsides. 3. Donny Greene in his comment at the end of Ch 3 says it this way: "Once you have the throttle control rule firmly understood and practiced and you can get the rear wheel spinning with a smooth roll-on, your bike will handle again." What if instead of spinning the rear, you time your roll rate so that the tire is hooked up and driving forward? I can see a viable reason to want to use a spinning rear wheel to help finish the corner, but it might be too much mid-corner even if it does work just fine for Casey Stoner.
  3. Steer for the Rear - Ch13 of TOTWII

    I believe that the answer to your question can be found in the last section of that chapter: Stable suspension. Perhaps re-reading Chapter 3 could help you see the whole picture more clearly.
  4. Steer for the Rear - Ch13 of TOTWII

    Remember that the 60% is not exact, the ideal weight distribution depends on the bike and also the tyres. I don't know the answer for sure, but logic suggests that if the front wheel is not lifting all the power is going into forward motion (minus power train losses, and anything wasted by rear suspension movement). So even if the front is off the ground, but is not lifting or dropping, all the power is going into forward motion. My observations while at the track seem to support this - an RSV4 had overtaken me before the chicane going onto the start/finish straight and just after that chicane is a crest which most bikes will wheelie over. I had tucked in behind the RSV4 on my 1098 and he wheelied while I didn't, which allowed me to pull alongside. Not sure whether this was rider skill or wheelie control but the front wheel of the RSV4 then hovered at a consistent height and the RSV4 was able to pull away. Of course it has a lot more power than my 1098 anyway so that's a factor too (he may have been wasting power and still have enough to pull away). But that particular rider is a nutcase so there's that factor too
  5. Yesterday
  6. Development

    Not the same, but at least it compare handling. Weather conditions will also matter here, which does not appear. Data from MOTORRAD magazine.
  7. Development

    Thank you for the link, it does tell about performance development in a straight line for the past two decades. It also show how big tolerances there still are - just compare particularly roll on times for for instance the GSX-R600 from one test to the other. What unfortunately cannot be read from these numbers is how fast they will go around a given circuit.
  8. Development

    Still haven't found it yet, but you can chew on some of this data. maybe copy/paste into a spreadsheet??? https://www.sportrider.com/tech/sportbike-performance-numbers
  9. Steer for the Rear - Ch13 of TOTWII

    This is pure speculation but I'd imagine that the front wheel begins to lift at a point well above 60% weight distribution. But if you could instead find a balance point where all of the power being used it for propulsion than lifting the front wheel, where would that be in relation to the ideal 60%?
  10. Steer for the Rear - Ch13 of TOTWII

    When you start wheelying some of your power is lifting the front wheel, instead of being translated into forward motion (speed). So if you are interested in lap times, you want all of the power you are requesting with the throttle to go into forward motion when exiting a corner rather than lifting the front wheel. If you are also interested in enjoying yourself you don't mind the wheelies coz they are great fun The most obvious demonstration of this wasted power is race starts where a rider who wheelies immediately loses tenths to those who are not. From my own experience, the time lost when doing some wheelies on corner exit is negligible and you can ride it out with the front wheel at a consistent height off the ground until the next gear change, which often puts the front wheel back down. One thing to note is that it's easy to have the front wheel turned when it touches down again if you wheelie while leaned over. There are few things more satisfying than wheelying out of a corner while leaned over, touching down with the front wheel turned slightly, but keeping it pinned, relaxing your arms on the bars and riding it out without having a massive tank slapper. On the dirt bike you can even do this while the rear wheel is spinning and roosting the rider behind you. Especially if that rider is your mate with whom you've been having a roosting war for years
  11. Steer for the Rear - Ch13 of TOTWII

    One the bike is on trajectory, we don't need the front anymore. The rear tire can support the full weight of the rider and bike combination. The power applied extends the suspension and yes the load to the tire increases. Fortunately, friction is directly related to load applied so therefore the load resists the tire sliding. Assuming we're talking about fresh rubber and not concerned about longevity, why do we care about having 40% of the load on the front. Why not get the power to the ground to the maximum that it translates into forward motion?
  12. Steer for the Rear - Ch13 of TOTWII

    We care the most about inducing the 40/60 weight distribution via throttle control when we need maximum performance from the tires and the suspension, when cornering on asphalt as fast as possible. If, while cornering like that, we put more weight on one tire, we compress that suspension and load that tire beyond the optimum state or conditions. The suspension becomes harder, the contact patch becomes a little bigger and the profile of the tire less pliable. Following the irregularities of the pavement is more difficult for the tire. The rubber becomes less elastic and it changes its shape more slowly. Once the weight carried by that tire while cornering hard reaches a crtical point, the available traction that the over-loaded tire can offer rapidly decreases. During a leaned wheelie, all the weight of the bike and the rider is on the rear tire and on the rear suspension. That tire would not be able to develop the traction demanded by the lateral forces of extreme cornering, which normally surpass the value of that weight. The wheelie always happens during the way out of the corner and at a lean angle that is much smaller than the max lean angle required by that turn. If the rider tries to wheelie the bike at that max lean angle, when the lateral forces of cornering on the contact patch are close to the max, the tire would slide. The tire would not slide only if the rear contact patch has been unloaded enough from lateral forces in a way that its performance can be reduced by the the extra weight.
  13. Last week
  14. I have not heard it said like that before - this is how I've heard it stated repeatedly: It is easier to teach a fast rider to stop crashing, than a slow and safe rider to go fast.
  15. Development

    That would be nice
  16. Just tossing this out if anyone has seen this. I found it on Amazon Video and only intended to watch the first 30mins or so but found myself staying up late to watch the entire 2h 18mins. It was awesome and I thought well put together and showed some of things the behind scenes story of 6 Aliens of MotoGP. One part stands out is the statement (objectionable to me): “A fast rider can learn to stop crashing but a slow rider cannot learn to go fast.”
  17. Development

    There’s an article with an objective performance data comparison of vintage vs modern sportbikes. Maybe later today I’ll see if I can find it again.
  18. Development

    Thanks, but not really. If you compare an old superbike to a new model, the older will be slower. It may be better at some details, but overall the modern bike will reign supreme. That's why I wonder how and old superbike would stack up against a current standard or sports tourer. Is the suspension better or worse on a 1992 CBR900RR than what you find on the CB1100RS of today, for instance? Or the new Z900. What about brakes? Handling? I'm curious because I personally believe 25 year old superbikes, as they were new, can still beat many current "normal" bikes when it comes to suspension and handling, and match them when it comes to the brakes. But I cannot be sure.
  19. Development

    Is this what you meant?
  20. Development

    There was a magazine that did a comparison like this....I saw something about it online. Maybe I can see if I can find it.
  21. HP4 Race

    See one!???....you tease! I'll bet you rode it didn't you....!??? And don't lie to me cause, I'll find you.... j/k :-)
  22. That would look like me getting out of the driveway - LoL
  23. Steer for the Rear - Ch13 of TOTWII

    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). And it makes sense to me. But there's a part of me that having a hard time with it and it's the mantra about 40/60 F/R weight distribution and using the throttle properly to arrive at that ratio and NOT exceeding it. Then that chapter goes on to point out that one could lift the front while leaned over and the bike will continue through the corner. I've seen it done many times (on TV, haven't experienced it myself). So if this is the case, why do we care about 40/60? Looking through the forum, I came across another thread where I somewhat asked a similar question regarding roll-on rates...which tells me that I've got plenty to understand about the topic of throttle management.
  24. Development

    To those who have ridden a lot of bikes over the years - if you took the best sport motorcycles from yesteryear and put them up against the current bikes of the same size but less sporty, fitted them with the same tires (where possible) and sent them around a race track, which would win? I'm asking because people have told me for quite some time that modern bikes, even budget bikes, are so much better than the stuff just a decade old. In my experience, my FZ07 has suspension no better than what many bikes could offer in the 80s, so I do not buy this. However, I could very well be wrong. So what if you teamed up something like these pairs, do you reckon the latest would beat the oldest every time? Or would it be the older sport bikes taking the honour? 1992 CBR900RR vs 2017 CB1000R 1993 GSX-R750 vs 2017 GSX750S 1994 ZX-9R vs 2018 Z900 1994 FZR600 vs 2017 FZ6R 1994 916 vs 2017 Multistrada 950
  25. HP4 Race

    So. Had a chance to see one of these in person. It's impossibly light and well balanced.
  26. We got some winter here and I took my Virago-come-scrambler out for a spin. Hard work! I have been riding a lot on winter roads on bicycles when growing up, as well as 3 winters on motorcycles before, but this - at about 530 lb - is by far the heaviest two-wheeled vehicle I have taken onto snow and ice. The tyres didn't impress, either, and combined with my limited skills when it comes to playing made things less than elegant. But at least I got to spin up some figure eights for the first time in my life, although they also proved the expected lack of talent. Still, I had fun, but during my commutes I stay away from playing since the front tucks every time the rear starts to spin up - I'd rather stay upright than topple over trying to look cool
  27. Steering Video No Bs Bike

    That the surfaces the bike was rolling across were not completely flat, coupled with a profiled tire, would be a big clue. Add to that what happens with front tire friction when a bike is leaned over and what that in turn does to the bars and you have more clues.
  28. Steering Video No Bs Bike

    The bike on ice was very interesting...and funny The last video...what made it change direction like that? This is why race bikes should always have a dead-man switch.
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