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Hotfoot

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Everything posted by Hotfoot

  1. Not necessarily - I wasn't attempting to evaluate the rider's technique overall, I was just looking at his lines based on your post. I'd have to watch again to have any opinion on his general technique. I didn't have the sound on, so I didn't hear his throttle control, and there is very limited info available with a camera view like that. All I can say is that his lines looked reasonable and I didn't notice anything particularly sketchy (like abrupt slides), and he seemed pretty consistent. He seemed to pass effectively which indicates that he was not getting "stuck" visually on the rider in front of him, probably he has a good wide view, which is of course a huge key to overall speed. What sort of maneuvering did you see that you wish you could do?
  2. In watching the video, it looks to me like he does straighten out the corners, except for where he is dealing with traffic and has to take a different line to pass. He consistently comes in tight to the apexes and uses all of the track on the exits, except where it doesn't make sense because there are connected corners and he is setting up the next turn point. In fact at one point I noticed he was passing and had to hold a tighter line on the exit and as a result he couldn't get on the gas as hard as normal and the guy he was trying to pass passed him back, on the outside. What specifically do you observe that makes you say it looks like he doesn't care about straightening the corners?
  3. I'll also add that I'm not sure about other brands, but I have ridden on some Dunlop slicks that had cords starting to show through on the rear tire and they still had good grip. I was only running a medium pace but they felt fine. It's certainly not something I'd recommend doing and I'd not do it on my own bike, ever, but it seems like as long as there is rubber left - even if thin - there is still some grip, as long as the tire is able to get, and stay, warm enough. I'm not sure whether that would be true for other brands or for street tires, and when you factor in actual AGE that is a different conversation, since the rubber can get dried out over time and lose grip. In regards to profiling, I rode on someone else's worn front tire and the profile had changed enough that I felt a huge difference in handling, particularly in one direction versus the other, I felt REALLY uncomfortable riding on that tire. I've also ridden on a street tire that had a ton of freeway miles on it and was squared off (flat in the middle) and I found that quite disconcerting, too, it was hard to turn initially then dropped rather suddenly into the lean and I didn't feel like I had good control of my lean angle.
  4. When tire is very worn and the rubber is thin it is much harder to heat up the tire and keep it warm, that is the biggest thing I notice on a very worn race tire, or in some cases the tire profile is changed through wear which can change handling.
  5. Where do you want it posted? I can move it for you.
  6. I think he is talking about just the bar end, the crash protection slider (also sometimes a weight for reducing vibration) which is just screwed in the end of the bar.
  7. Oh, this is hilarious, for two reasons - one, I meant to type RACING story but apparently the typing app on my phone (I use Swype) decided I meant 'teaching' and two, red velvet furniture and a sexologist, OMG. I think I was at that Laguna school. My husband and I spent most of the free time huddled in our little cargo trailer trying to keep warm!!
  8. FOSSILFUEL!! Welcome back, my old friend, so great to have in here again. I think you should start us out with a teaching story, got a fun one to share? I have a question for you, as another rider who has raced a lot of different types of bikes: what bike or race class has been the MOST fun for you?
  9. Riding a curved on-ramp at the speed limit with a cop behind you.
  10. This sounded a little odd to me so I watched the video. Here is what jumped out at me: The title of the video is: Ninja 300 shock causes tire wear. The first thing he says is that the bike has a stock shock, and that he is suggested this riding change as a way to compensate for that stock shock. My interpretation of that is that you could manage the problem temporarily by adjusting your riding but what you should REALLY do is check your suspension settings (or possibly the geometry) to FIX the problem, by setting it up so that the tire is not so unloaded or bouncing at corner entries. I'd also verify your tire pressure, as I suspect that tire pressure too high could aggravate the problem. I'm not a suspension expert and you should ask someone who is - but from what Dave Moss said, it sounded like the shock was not keeping the tire planted so maybe slower rebound, and possibly softer on compression, might help to keep the rear tire from bouncing up and down. Have you had the sag set properly on your bike for your weight? Have you checked the spring rate to see if your weight is within the recommended range for it? It seems like a better plan to fix the mechanical issue rather than changing your riding style to compensate - unless, of course, you are just trying to get through a race or practice day like the rider in the video. Also... there is a WORLD of difference between throttle at 30% on a Ninja 300 and throttle at 30% on an S1000rr! 40hp versus 200hp and the BMW only weights about 60 lbs more than the Ninja. I don't think I'd assume that piece of advice would apply the same from that bike to yours, you might get a different effect. For the sake of discussion, what sort of effects do you think you would notice on your bike's handling if you put the throttle on 30% entering a turn?
  11. Bashir, I think we should move this question to the Tech/tires section so our Dunlop tire expert can take a look at it. Would it be all right with you if I moved it your post?
  12. Have you tried working with a coach or friend, or looking at photos, to compare your left vs right body position to see what you are doing differently? Or is there a strength issue on that side? In the absence of any other info I'd look at how you are holding the throttle, as rolling on the gas as the biggest difference between lefts and rights. Are you doing something awkward with your arm, shoulder, or body to give yourself room to twist the throttle? Have you tried the "screwdriver" grip on the throttle to help prevent your wrist getting bound up when trying to roll on hard?
  13. Laptimes are mainly used for students who want them, to see evidence of their improvement through the day. Or sometimes to compare to their buddy's times, for bragging rights. It happens that as techniques improve, especially visual skills, the rider can feel like they are going slower - less rushed, less frantic, less fearful, sometimes using less lean angle- yet they are actually going a lot faster. Laptimes really help make that real to the student. It is rare for coaches to use the lap time data for coaching, unless a student knows/races that particular track and has a specific lap time goal in mind. We have better tools than a laptimer for L4 students, like video or the BMW datalogger, which collects WAYYYY more info, if a rider is specifically focused on improving laptimes. It's a lot more effective to use video to find areas of improvement. I think we do have records of prior laptimes but don't know that they are used for anything; Trevor has an incredible memory for returning students and can usually say whether someone is riding faster than they have before, or whoever coached the student before usually knows too.
  14. You should start rolling in the throttle after you have completed your steering action (reached your desired lean angle) AND the bike is pointed in the direction you want to go. Can you roll on TOO soon? If you did, what would happen to your line?
  15. The logic in getting more weight on the front, as I understand it, is that more pressure/weight on the front tire will increase friction (friction increases with weight) and also flatten the tire out more, making the contact patch larger, which doesn't increase friction directly (friction is not dependent on area, just weight) but CAN help the tire because too much pressure in too small an area can (I think) overheat the rubber and reduce the coefficient of friction, which WOULD reduce the overall grip. (Note - this is me giving you my own understanding, this is not superbike-school endorsed info.) Getting more weight on the front also can tighten up your steering by compressing the forks - but you can also get a similar effect with hook steering or changing your geometry or suspension settings. So that all works well for turn ENTRY, however once have turned the bike and have reached your desired lean angle and are pointed in the direction you want to go, if you don't get on the gas you will just keep slowing down. The best scenario for traction once you DO roll on the gas is: 40/60 weight distribution. Thus, the throttle control rule, "Once the throttle is cracked on..." So, the way I look at it, is while you are still slowing down and getting the bike turned, the weight on the front is a good thing (to a point - obviously using too much trail braking while turning can exceed your front tire traction), and once you are back on the gas, 40/60 is the way to go for best stability (we are no longer making lean angle changes at that point) and traction. Does that make sense? Do you remember from level 1 exactly WHEN you are supposed to START rolling on the gas?
  16. Ah, now I see where your question is coming from, this makes more sense. I agree that the danger of applying the brake too fast is in applying it TOO MUCH. If you are really, really good and know exactly how much brake pressure is needed and have good enough control to get right to it instantly, then YES, go for it, that makes sense. However, not everyone is that good so it is understandable that riders are taught (or learn through experience) not to snatch the front brake. There are things that happen that do change with time, as you can observe and experience directly for yourself. The front shock compresses as you shift weight forward, this takes time - not a lot, but it is not instant, because the forks do actually move and that takes some time. Same with front tire flattening; it's very fast, but it ain't instant, and a slow motion camera would show this, the tire has to actually flex. Then there is the rider - a time lapse video would show the effect of deceleration/weight transfer on the rider. Because those things are occurring, the situation can and does change over time - for example, a hard grab of the brake can cause the rider to tense up the arms and fall forward, and the effect can worsen as the front end of the bike dives down, so what should NOT have been a front tire slide (based on brake pressure alone) can become one due to the increased load on the front due to the rider's weight and restriction of the bar movement. This is where it gets complicated to reconcile theory and real world experience - it is difficult, with theory alone, to account for all of the variables created by the bike and rider. There is a great discussion of this in The Soft Science of Motorcycle Racing, I will have to look and see what chapter that is in.
  17. I think the simplest solution would be for you to go ride and try it and see what actual results you get. It shouldn't take a lot of muscle effort to just sit on the bike, but when braking hard or trying to hang off it will take more. During the braking and hanging off times, try doing it with abs slack, and then try tightening your whole core and see what gives you better support and less stress and muscle fatigue on your back. If you want to get really serious about getting strong, flexible, and comfortable on the bike, get into yoga. I coached a guy recently on body position - he was 2-3x older than everyone else in the group with him and way more flexible and strong on the bike. I mentioned it and he said he started doing yoga and was astonished at the difference it made. I've heard this enough times to take it quite seriously, it definitely seems to work.
  18. Well, the term swayback comes from horses and usually evokes an image like the one above. In people it's where your belly pooches forward and your butt sticks out, lower back curved too much for good posture. Core strengthening improves this.
  19. OK I read back through this whole thread, and yes, bringing in Throttle Control Rule #2 seems to have added some confusion, as I personally got stuck on trying to discuss the throttle control rule. After reading back over it all, it seems that the OP's real questions was, does it really cause any problem to let off the gas fast or pull in the brake abruptly, it seems like people do it all the time.... I think the answer to that is situational, depending on how much traction you have and how much you are willing to upset the chassis. And also, of course, how fast you need to slow down, and how accurate you need/want to be when setting your entry speed. Example, if you are riding your S1000rr in first gear, wide open throttle, 12,000 rpm and you instantly chop the throttle you will feel a very abrupt change in the bike, potentially enough to affect your accuracy in an upcoming turn. However, if you are in sixth gear at 4000rpm, wide open throttle, and let off abruptly, that's not going to be such a violent change, it may not bother you to rock the chassis that amount. The weight shift is even more pronounced with braking, of course; but it is a matter of priorities. Upsetting the chassis with abrupt brake application may very well be worth it, especially if you need to get it slowed down in a hurry. For sure I can think of corners where I am coming down from high speed to low speed, traction is good, I am straight up and down, where I let off the throttle and bring in the brake as fast as I can - upsetting the chassis is OK with me, I know the front will dive down hard, but my priority is braking in the shortest possible distance and the majority of braking is done at the beginning and I need time for gradual release as I enter the corner. But I can also think of places where I am entering a corner leaned over, or the surface is bumpy, and I apply the brake more gradually to maintain the best suspension/traction scenario, to avoid bottoming the forks or overloading the front tire. One thing we have been taught is that if you slam the front brake on so fast that there is no time for the weight shift to the front tire to increase your traction, you can slide the front tire. Is that a problem? Maybe not, if you are going in a straight line and don't scare easily. Lord knows we see pros doing some really scary things on the brakes, things most of us don't really want to have happen on a Sunday ride (like stoppies, rear wheel hop, back end wagging around, back end stepping out, etc.) I'm going to run this question by Dylan and/or Keith and see what exactly Dylan was trying to communicate and get more details on different scenarios - braking while leaned over, wet conditions, etc.
  20. If your abdominal muscles are weak and you leave them slack and loose when trying to support your upper body, the looseness of the ab muscles will cause your back to hollow (swayback), which forces your lower back to take all the load of holding you up, and the looseness of the ab muscles combined with the tightness of the back muscles will tend to tilt the pelvis (either the cause or the effect of the swayback). Tightening the abs creates a column of support (your entire core, front, sides and back) that allows you to use a broader range of muscles to do the job of supporting your upper body, prevents the pelvis from tilting backwards (hollowing the back) and preventing your lower back from having to do all the work. Does that makes sense?
  21. From Keith "Any plan is better than no plan."
  22. So here is how I take it: the rule says "calculate the roll-off as carefully as you would a roll-on" and I take that to mean, make a plan on how you want to do it. I don't think it means it always has to be slow, and maybe in certain circumstances (good traction, straight up and down) it might not even need to be smooth, but it does need to be considered. If it is too slow, it could delay braking, and if it is too fast it could upset the chassis. I learned the hard way that just snapping the throttle off is not always a good idea; when riding in the rain, going fast, I rolled off abruptly (as I had often done in the same exact place) but the sudden slowing and slick conditions made the back end come around. OOPS, not what I wanted to have happen! I also found out at COTA in the rain that BMW actually accounts for this in the traction control, in Rain mode. If you abruptly go from full throttle to off throttle and decelerate too fast for conditions the bike will feed some power back to the rear wheel to regain traction. A little shocking to experience that but it's a good lesson in the importance of calculating your roll off, instead of getting in the habit of just snapping it off every time.
  23. Nice! Was there any particular breakthrough that made it great, or was it just plain fun?
  24. At high speed wind drag is a major source of deceleration. That is NOT the same effect as using the front brake. Wind drag is a tremendous factor at high speed, and practically a non-factor at slow speeds. Wind drag is proportional to velocity SQUARED so increasing speed causes a huge increase in drag. Not saying the whole throttle control rule #2 is about wind drag, but I AM saying you can't assume a hard-braking slow corner is the same as a slow or non-braking corner at very high speed. The radius of the corner will be substantially different so the steering effort is different, the forces on the bike are different, what the rider needs from the geometry is different, use of the brake is different, amount of slowing required is different, etc.
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