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Hotfoot

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Everything posted by Hotfoot

  1. S1000RR Rear Suspension

    Ok first of all this is TOTALLY awesome that you have this data to post! The datalogger is fantastic, and I'm glad to see you using it, what a great application. That second chart is terrific, lots of information there. At first glance at the second chart things look pretty even from one side to the other, your lean angle is not drastically different on rights versus lefts, but on closer examination the throttle position versus lean angle does look somewhat different - that top red line showing around 75% throttle at 40+% lean angle and some of the yellow and orange at 45-50% are more apparent on rights than lefts, and the slip rate seems, in general, a little higher on the rights but not much (looks like more data points in the >10% range?)... and maybe the characteristics of the corners on that track are what is causing those differences. I think I see the problem - the Michelins are not "adapting" sufficiently to your situation. Do you know if the tire damage is more within the first few laps or sessions or at the beginning of the day versus later? That might help determine if it is cold or hot tear, it sort of looks like hot tear to me (the tears look wider and shallower than I'd expect to see for cold tear) but for sure I am not an expert. But the fact that a 2 psi pressure increase seemed to improve the situation would support that as well - if you have a chance next time to check tire temperature and pressure before and after riding (straight off warmers versus coming off the track) that should help tell you whether it is hot or cold tear, that article above has some specifics of what temp/pressure rise to look for, and/or the tire rep should be able to tell you what is optimum operating temperature/pressure for that tire, to compare to what you are actually getting. If it were me I'd check the alignment on that rear wheel - not sure whether that would or could have anything to do with this type of uneven tire wear but it's a really easy thing to check, and a good idea to do anyway. Then, if the tire pressure and compound seem correct for the track (per the tire rep), I'd next try softening the rear suspension and see if that helps, since that could contribute to hot tearing by making the tire work too hard because the suspension is not compliant enough. Also check the spring rate recommended for your weight and see if you are within range, if the rear spring is way too stiff for your weight that could be contributing to the problem. Since you have good photos AND access to the wealth of information from your datalogger, you could try reaching out to Dave Moss to see what he thinks on the suspension side, I think he does analysis like that and it would probably be refreshing to him to have all that data available to work with. Dataloggers are such an amazing tool!!
  2. S1000RR Rear Suspension

    I'm not a tire or suspension expert by any stretch, but here are my thoughts: 1) Since it only is happening on one side (and you are riding multiple tracks) that would imply an issue with riding style - unless the tracks are all very right-handed - less likely that a suspension or setup problem would only affect one side. A rider that drives much harder while leaned over farther on right handers might experience different tire wear on that side, though, does your lean angle or body position look significantly different from one side to the other in photos? 2) I'm not a suspension expert but this does look like tearing, is this is multi-compound tire, and is the compound on that part of the tire super soft? Personally I have only seen that kind of wear when the tire was too soft for the for the track surface and/or if temps were out of range (hot tear or cold tear). You might try asking a tire vendor what compound they use on the tracks you run - especially since you didn't have the issue with the Q3s, could be the tire is just not appropriate for the surface, or that it has a super-soft compound at the outside edges and THAT is too soft for the surface. 3) The width of the worn area looks even to me, doesn't show the wave or wider/thinner areas that you might expect to see if suspension was the issue. Do you run warmers? How much does the tire pressure change from coming fresh off the warmers to coming off the track after riding? What sort of outside temps were you riding in, and do you have to sit for long between coming off the warmers to riding at speed on the track? Dave Moss's various websites and videos are a great source of info, here is one that might be helpful:
  3. S1000RR Rear Suspension

    I asked our chief mechanic at the school, here is his response: >> The eccentrics are in the stock position. There is no "wrong setting". Tearing like that comes from wheel spin. Depending on what mode he runs in or what his traction control is set to will vary the wear. Mid Ohio for sure has some straights coming off right handers and a kink so there's gonna be some serious drive in those spots. The position of the wear would indicate getting on the gas late and hard. >>
  4. One day I was putting a whole series of riders on a bike to work on body position (part of the level 2 off track exercise) and one guy, who was in his 60s, was strikingly more flexible on the bike than everyone else and was able to get into a very hung-off position that was really stable and strong. I commented on his flexibility and he said he had been doing yoga and it really helped. I certainly agreed with him - he was flexible and strong for any age, let alone for someone in their sixties. I was quite impressed. The flexibility in his hips, legs and ankles (compared to everyone else) was the most noticeable when seeing him on the bike.
  5. Training the cornering weak side

    When you sit on the bike on a stand, and get in your normal hanging off positon (assuming you hang off for corners), can you let go of the bars and still feel secure? Is it easier on one side than the other?
  6. New Trailer Setup- Weight and Balance

    We've towed a variety of different trailers and as you stated above, there is room to get it a little "wrong". As long as you are not extreme in loading the very back or very front unevenly you shouldn't have much trouble, so putting the bike(s) over the axles ought to handle it without having to get it right within a couple of inches.AS an example, think of toyhaulers - they have a huge amount of trailer weight in tanks for fresh water, gray water, holding tank, and large fuel tanks (on board fuel station) and the loads very considerably between empty and full and in between, but the trailer hauls solidly regardless (well, ours have, anyway) of which tanks are full or empty. Those tanks are placed near the axles, of course. Personally the only time I've had trouble was when the vehicle hitch was too high so the trailer was not level (it was high in front which made it want to wag) or if ALL the weight was in the back of the trailer, which I accomplished once by loading a small trailer (14 foot) with a riding mower and nothing else, and putting the mower in the very back. That didn't feel good to tow, but I hadn't been paying attention to how I loaded it since I was only going down the street. I wouldn't do it that way again.
  7. Thanks for posting this, so glad you had such a good result AND saw it translate to your street riding, it's cool that you were able to go ride a good fun road so soon after school and find out what had changed in your riding. Look forward to seeing you back again!
  8. Outgrow stock suspension???

    Yes, it certainly is possible that your change in corner speed has outgrown your stock suspension, and it sounds very likely, based on your description. It's incredible how much difference an upgraded suspension can make in the bike's handling and in the rider's confidence, due to better feel and more predictable handling.
  9. I'll be there, come say hi! I'm Laura (Laura the coach, not Lara in student services, who you will definitely meet), I'm about 5'3" with long brown hair and I'll be in one of the white staff shirts - or more likely in a CSS jacket or black sweatshirt, since the mornings are usually very cool at Laguna Seca.
  10. If you look at the rider's body movement, you can see that it's not a smooth ride. I'm thinking a combination of bumpy road, wind buffeting (the riders are pretty close together and the speeds are high, getting up into the 150mph range), and a much stiffer suspension and tire carcass than you'd see oh a street bike, plus a bike setup that is much twitchier than a cruising bike so it reacts more. Also the hard acceleration and braking may cause the rider to add some unwanted bar input, you can see from the rear view how much the riders are moving around. On my racebike at one particular track there is a high speed section (150-170mph range) close to a wall and the wind buffeting from the wall or any nearby rider is very noticeable, it wobbles your head around and makes the bike move around, you can feel the bars move, even though you are going straight. Have you felt your handlebars move in wind or when passing a large vehicle?
  11. New Schuberth lid

    YES!! The SR2 is MUCH better in that regard, for certain head shapes. Mine, for example. I have a small head and had the same issue with the SR1 sitting too low on my head but I rode 2 days last week in the new SR2 model and I could see out of it just fine. Really well, actually, because the field of view is very wide. The ventilation was good, too. The Schuberth folks told me a while ago that they thought the SR2 would fit me better and it definitely does, it's definitely worth a try. You probably know from your SR1 that these helmets break in as you wear them, so it is best to get one that feels a bit tight when brand new.
  12. Can Quick Turn Be Overdone?

    The short answer: you have to work up to it and feel it out. The longer answer: Testing the grippiness of your tire must be done gradually, the idea is to increase lean angle gradually so that if the tire begins to slide there is some warning and opportunity to save it. The most pro coaches I have talked to on this advise gradually adding a little more lean at a time (corner after corner, or possibly even in the same corner if it is a long one) to feel out the traction, as opposed to just whacking it over to maximum lean and hoping for the best - because if you go too far too fast you will not have enough time to "sample" the traction and see how it feels, and know when you are approaching the limit. Some tires will have a specific feel to them when they are cold: the Dunlop slicks, for example, have a tendency to make the bike want to stand up in the corner and that is a good indicator that they are very cold. The carcass is stiff and reluctant to flex so when you lean into the corner it resists and sort of pushes the bike back up. Some other tires just feel a bit "wandery" in the corner, like they are sort of weaving around slightly, instead of feeling planted. If you have ridden in rain or ridden dirt bikes in the mud, you can recognize the feel of little slides, and little slides like that are your warning that you are at about the limit of traction for the conditions and the tire needs to warm up more before you can lean over any farther. It is a great exercise, when opportunity presents (winter is coming!) to pay VERY close attention to how your tires feel when stone cold, to develop a sense for it with your own bike and your own tire brand/model. It is difficult to quantify how long tires will take to warm up because it depends on tire type, air temp, track temp, wind conditions, how hard you ride, etc., so the best solution I know of is to feel it out carefully.
  13. Newbie Greetings!

    Welcome! Glad to have you on the forum, lots of great info here. There is an article in the articles section on crashing that you might find helpful. For your question about diagnosing your track day crashes, the Track Days and Schools section might be a good place to put it, or the Cornering section, and we will see if we can help on figuring out what happened. Describing the one you recall the best would likely be the most productive since figuring it out will require us asking some questions about what occurred. You are also more than welcome to send me a private message and we can try to figure out the cause of the crashes, if you prefer that over posting it up on the general forum. Welcome aboard and we look forward to your participation in the forum!
  14. Brembo stuff

    That is a pretty bold statement. I disagree. There still needs to be a willingness to go fast, a level of tolerance for speed and G forces, and the visual and processing skills required to be located on the track and in control of the machine, not to mention knowing where to point it. IMO making the bike easier to ride helps free up attention and reduce crashes but won't make an average rider a superstar. Just look at today's bikes, you can buy a crazy high horsepower bike right off a showroom floor that has clutchless shifting and traction control and even electronic suspension, but move an average rider from an aged 600cc bike to one of those and see how much faster the rider really goes. Or just watch a superstar kid on a 1990 RS125 making mincemeat of a bunch of adults on 200hp liter bikes with all the electronic assists, you can see that often enough at a typical track day or race practice. I do agree that riders who learn on bikes that do all those cool things would struggle on an older bike without the electronic assists - just like many teenagers today wouldn't know how to operate a manual transmission car - but that could be overcome with some training and practice, I think the best riders would still rise to the top in either situation, I don't think the bike makes the rider.
  15. New from DC/ AZ

    Well, I'm not sure yet if I'll be there on Sept 10 but my husband will be, doing Level 4. He races, could probably tell you about local racing, WERA, etc. He is a regular Level 4 student and has done CodeRACE, and races with WERA (as do I), they are great to race with and come to Auto Club Speedway at least a few times a year, another good racing option for you. I hope you can get to CodeRACE, that will be fun and help you a lot with your racing.
  16. Spyder at CSS

    Never say never!
  17. Spyder at CSS

    Maybe this is only a half serious question, but I'm going to assume no, since it won't handle like a two wheel motorcycle. The visual skills would apply, of course, but no doubt lines, handling, lock on and body position would be different.
  18. Q3s starting to feel weird.

    From what you describe that does sound a bit too early for the tire to be having issues just from usage. Had you put in three full track days, especially if it was very hot or a very abrasive or one-sided track, I'd wonder if the tires were getting worn or profiled. At the school, yes, depending on the conditions - some tracks are hard on tires and keep in mind we have three groups of riders in a day so the tires get a lot of use in a day! The tires are checked continuously and changed often. 1000cc bikes are hard on tires, especially rear tires! The mechanic did say the Q3s last longer than the Q2s, and I don't personally have a ton of experience on the Q3s on my own bike. I used to use the Q2s a lot but mostly have been riding on slicks since the Q3s came out. I have ridden on them at the school, though, and I love how they feel, great grip and excellent, predictable handling. Maybe our tire expert can chime in on how many track days are typical for Q3s for a bike like yours, and/or how much heat cycling they can take before starting to feel different.
  19. New from DC/ AZ

    Sounds like you've got lots of plans, that's exciting! Chuckwalla is a fun track and I hear the racing group out there is friendly and fun, you should have a blast. Hope to meet you at Streets, are you doing CodeRACE or the regular school?
  20. Against the flow

    I agree that (a) choice of lines and good control of the bike are more important than body position and (b) riders can crash due to poor body position because of improper/uncontrolled bike inputs, like unwanted bar pressure. But here is a question for you - if you are going as fast as you can go, and trying to catch a faster rider, and you run out of ground clearance (dragging a peg, or your exhaust, for example) what you would change to try to go faster to catch that other rider?
  21. What happen here?

    This is what the school recommends as well, and it works. Yep, traction control cannot necessarily save you from adding throttle and lean angle at the same time - it's too much changing too quickly, there is not enough time for the traction control to react AND there is no time for tire feedback to warn the rider, which is why we always warn riders not to add throttle AND lean simultaneously. Just as an interesting note, I suspect the BMW S1000rr's rain mode could have prevented the crash, as it limits how much throttle the rider can apply based on lean angle, and I think it would not have allowed to rider to apply as much throttle as he did at the lean angle he was using.
  22. Limitations of CSS techniques?

    This is my understanding as well. The trouble is that it is not so easy to get fine control on the rear brake, since you are using your foot (which is encased in a racing boot!) and it is difficult to get the kind of fine control you can get with a hand lever. As mentioned earlier some riders that make use of the rear brake get a hand control for the rear brake, and that seems to make a lot of sense. Of course the best way to evaluate whether at technique works for you, is to try it for yourself and see what results you get. It is important to measure the result somehow, though, as whether it "feels" faster is not always a reliable indicator of whether it is ACTUALLY faster, so a GPS timer that shows acceleration/deceleration and shows speed at whatever points you want to see on the track would be very helpful. Or the BMW datalogger if you have an S1000rr. The CodeRACE program has a great exercise where the rider can ride through a corner multiple ways, and there is a visible speed radar that allows the rider to immediately see which technique resulted in the fastest exit speed of a given corner. It is incredibly enlightening. So - why is the rear brake so much more commonly used on dirt bikes compared to roadracing bikes?
  23. What happen here?

    Wow, John, look at that thread from way back in 2004, how did you find that? :) But yes it is very good info. And yes, I was asking about why the rider was weaving back and forth. You do see this pretty often at track days, riders weaving back and forth in an attempt to warm their tires - but it doesn't work. It can be dangerous, too - not just because a rider could crash doing it (that would be embarrassing!) but also because if you are unaware of another rider about to pass you and make a sudden swerve like the you could run into them. Good answer, faffi, on question 2. There are some training tools at CSS to help learn to control the Survival Reaction of wanting to chop the throttle when the rear tire starts to spin. The S1000rr bikes we use also have traction control. So here's another question for the group - do you think traction control would have prevented the crash on the video?
  24. What happen here?

    Would "adding throttle and lean angle on cold tires" be too simple an answer? You can hear him rolling the throttle on as he is swerving back and forth and the at the point where he is leaned over the most you can hear the tire spin up. Maybe he hit a slick spot but most likely the combination of lean and increasing throttle just exceeded the available traction for the tire - which was most likely cold, since he was just starting his session. The rear tire then slides out sideways, the rider lets off the throttle (you can hear it), the rear tire regains traction and whips back the other way, and then you can see the rider start getting pitched forward, and my suspicion is that he ends up putting pressure on the bars so that they can't move freely thereby eliminating any chance of the bike straightening back out. You can see the front end trying to correct at first but by the time he actually falls it seems like he is leaning heavily onto that right-hand bar. So, couple of questions back at the group: 1) What is a rider typically trying to do when they are swerving the bike back and forth like that, and does it work? 2) What should a rider do (or better yet NOT do) with the throttle when the rear tire starts to slide, and why?
  25. Limitations of CSS techniques?

    Here is a snippet from Keith in Twist of the Wrist II that I think applies, this happens to be about choosing a line through a corner: "The "everyman's ideal line" does not exist, and it never will. Different lines are the rider's own personal way of seeing and doing his job: A concatenation of his strong and weak points, dos and can't dos and machine limitations, and, of course, his SR threshold." I think this is why we call it the "art" of cornering, and to me, the differences in riders' style and application of techniques is what makes racing so interesting to watch - and the sport itself so fascinating.
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