harnois

Your #2 could be suspension, but I think your #3 is probably a lot more to do with tightening up on the bars, or hanging your weight on the bars when hanging off, or pushing on the bars inadvertently as you are moving into the hang off position. You say you only hang off when you screw up. I take you mean when you get into a turn too hot? That is exactly the scenario where almost all of us have the tendency to tight up on the bars. The higher handlebars on the 650r make hanging off more awkward in my experience. I don't think that there is anything inherent about hanging off ("the thrust center is misaligned from the center of gravity") that would cause the sensations you describe. Lots of people hang off all the time without having their front wheel sliding and squirming, even on bikes with soft and unadjustable suspension. Your #2 could be suspension maybe if you are making some really fast transitions. Making your transitions a little slower might work better with that kind of bike. Or maybe just making them smoother. Perhaps all of the stuff you describe here is from just riding the bike too hard in general. Based on the specs it's not a super aggressive bike. Not that I'm diss'n your bike or anything. I've had similar bikes and loved them but different bikes have different purposes.

When you are transition from left hang off to right hang off positions, or from not hanging off to hanging off, you should do it entirely with your legs, and not be pushing on the handlebars. And when you are holding yourself in the hangoff position you should be holding onto the bike with your legs, not your arms. I bet you are messing with the handlebars and causing the above sensations. Practice with your bike stationary on a repair stand or something like that. Or, just don't hang off - it's not really something you have to do except for the most extreme cornering - I personally rarely do it when riding on public roads. But even if you stay centered on the bike you still need to not be inadvertently pushing on the handlebars. Push on the handlebars to countersteer to change your lean angle, but try to relax your arms completely when maintaining a lean angle in the middle of turns. And if you are going to hang off, do it before the turn rather than transitioning to it in the middle of the turn.

The 636 is probably geared lower overall which makes up somewhat for the lower power, so the 0-60 or 0-100 capabilities of of the 2 bikes are perhaps not that much different. They are both limited by their need to keep the front wheel on the ground. However once you get to much higher speeds, say well over 120mph, more of the power goes into pushing you and the bike through the air. The 1000 will continue to accelerate beyond the top speed of the lower geared and lower powered 636. So the biggest difference between the 2 bikes is at very high speeds. At their top speeds the bikes are using almost all of their power just to counteract the wind resistance. Then consider that wind resistance I think is exponential, meaning it takes a lot of power just to get a little bit more top speed. Secondly, in the turn where you can't use full throttle on either bike, it makes no difference. So when you take those 2 things together it's easy to see why on most race tracks the difference between the times of the 600s and 1000s is not as much as most people would guess. They are leaned over most of the time and then the short spurts between tight turns there may not be that much difference in acceleration provided the guy on the 600 knows how to work the gears, but in the long straight the 1000 gets ahead by a few seconds. It would take very little difference in your comfort level on the 2 bikes to counteract the advantage. And to take advantage of that 1000 on those public roads shown in your video, you would have to have some long straight stretches and have the balls to hold the throttle full open for long periods of time and get up to some speeds that would be seriously hair-raising on public roads.

I have used the regular Pilot Powers on the track, for 3 to 4 track days back to back no problem, they had plenty of tread left for a couple thousand miles of street use after that. I liked them on the track because, at least for someone of my level, they seemed to provide very consistent performance for 3 or 4 days, and they also work fine on the street. So if that model is significantly less expensive than the race version you might want to consider just getting a fresh set of those. I've not used the Race version but I seriously doubt you are going to fry those in one day of track riding unless you are famous. Here's an excerpt from Keith's article "The Bands of Traction" in the Keith's Corner section of the forum:

Here's another post about the same problem, with similar responses: "Once I Get Past A Certain Lean-angle, The Bike Wants To Keep On Leanin" http://forums.superbikeschool.com/index.ph...pic=869&hl=

Nice pic btw, noth'n but guardrail and sky behind you!

You posted a pic of your rear tire but the phenomenon I was talking about was more to do with the front tire. Anyway it does sound like a fresh front tire is very likely to help. And meanwhile, as long as there is rubber on that tire, I'm not suggesting that you have to rush out and replace it. I normally do like you are doing and wait until just before a track day to put on the fresh tires. I've been through a lot of tires on street bikes on public roads, commuting and touring, and the wear pattern I always see is that the rear tire wears out in the middle, but the front tire wears out somewhere between the extreme edge and the middle, because that's the part of the tire getting used the most in my more moderate public road lean angles. And when the tire gets to be in this condition, the normal neutral handling gets all messed up - I am forced to keep pressure on the bars to get the bike to hold those moderate lean angles, it tries to stand up out of the turn and I have to fight it, but then if I lean lower and get passed that flat worn part of the tire more towards the edge, the bike becomes neutral again. That transition from having to push on the bars to neutral handling feels exactly like you described. The front tire in this condition also causes some wobbling on bumpy/swoopy roads, so it just all around starts to suck when it gets bad enough. The following is just my theory/understanding as to why this happens: If you roll a coffee cup on a table it will curve instead of rolling straight, because the bottom of the cup as a smaller radius than the top of the cup. The tires on motorcycles, when leaned over, are affected the same way, causing the front wheel to want to turn toward the inside of the turn which would make the bike stand up. Normally this is canceled out or balanced out by the trail. "Trail" as you probably know is what keeps the front wheels of a grocery cart pointed in the correct direction, and it is also used on the front end of a motorcycle for basically the same purpose - it keeps the front wheel pointed in the direction that maintains balance or neutral handling. "Neutral handling" means the bike will maintain its lean angle with no pressure on the bars. When the front tire is worn as described above, and you reach the lean angle that uses that worn part of the tire, the contact patch becomes wider, which means that coffee cup effect gets more leverage, which causes the front tire to want to turn into the turn and drive itself under the bike, or in other words makes the bike want to stand up instead of maintain its lean angle. When I have a front tire that's seen a significant amount of track time I don't have this problem, because on the track I'm wearing out the very edge. But for so many reasons I just don't see those kinds of lean angles often (or ever) on the street. >> Im wondering if its me starting to hang onto the bars a little to tight and giving it some bad input?????? You could put your bike on a repair stand, or maybe just the side stand, then get on and get in your hang off position, then let go of handlebars, you should be able to hold your body in the hang off position with your hands not even on the bars. Then the more difficult thing is to make sure that is true at all times through the turns. I have often found myself reverting back to supporting some weight on the inside handlebar. When ya hit bumps or swoops in the middle of turns that weight on the inside bar may cause the bike to wobble some, and that's what always alerts me that I'm doing it. I like riding on rougher back roads as practice because they force me to be very conscious of staying loose on the bars. The harder ya ride the more noticeable it is. It could be that at certain lean angles you are hanging off your shoulders more, and/or starting to put more weight or pressure on that inside handlebar which would cause the sensation you describe.

I've used those tires a lot and I like them. I have an '06 gsxr-600. I've also used the same tires on a YZF600R. How worn out are they? I've found that on any tire, if I use them on the street a lot, there's a certain lean angle I'm comfortable with on the street, and the profile of the front tire eventually develops a flat spot at that lean angle, which messes with the handling. When at that lean angle that's using the flat spot, the contact patch is wide, and that makes the bike want to stand up, but then when it gets passed that angle, the contact patch is narrow again, and that makes the bike want to lean down more. Seems like what you are describing. Even though my rear tires usually wear out twice as fast as the fronts, I usually replace the front tire with the back for this reason. If you are used to some other tire then it could be the profile. They do make the steering feel a little different from other tires but I never had the feeling of it about to lowside. You didn't answer what pressure you are running. I run them about 30 on the track, but sometimes a lot higher on the street. I wonder if your problem might have something to do with suspension? Cornering forces will cause your suspension to compress. Maybe you should try increasing the preload on the front. Have you ever checked the sag?

This bike looks like it'd be really fun: http://www.yamaha-motor.com/sport/products...596/0/home.aspx And Yami seems to be emphasizing its claimed 71mpg.

I had a 2001 yzf600r, it got at least 50 in normal riding, around town commuting or spirited backroad riding. It occasionally got up to 60 mpg if I did a lot of easy cruis'n. it never got less than 50 except on the track. This bike had carbs. I sold it with 67000 miles on the odometer and it was still getting the same mpg. I really wonder what it takes to actually wear out these sportbike motors. Now I have a 2006 gsxr600. For the first several thousand miles I put on it, I got 38mpg, sometimes up to 42. My friend got a 2008 gsxr600, and he was getting 49mpg. I asked him what kind of gears he was using and it was clear that he was consistently using higher gears and lower revs while street riding. I did the same and now I get around 48 to 49 mpg consistently. So it appears the gears you choose can save you some money. Most of the time now I'm riding between 4k to 5k rpms and am in 6th by the time I get to 50mph. Sounds like a boring way to ride, but I shift to the fun gears in short spurts on the curvy sections. My KLR650, all loaded up with 2 people and luggage, and riding on jeep trails, gets 50mpg... but it doesn't go very fast.

Number 1 for me at this point in my learning curve is the Visual Skills - Trying to look further ahead the "wide view" is new for me and thus currently takes up a lot of my attention. I look forward to the time when this becomes more natural for me. Quick Turning demands a lot my attention in chicanes and esses but not so much otherwise. Although I think I've fairly decent at this already, at times I consciously try hard to lean it faster and further. In esses especially, quick turning feels like THE limiting factor on how fast one can go and still stay on the track, so it's not like I'm ever going to be done trying to do it better. Throttle control and body position seem second nature or subconscious to me now so I don't normally have to pay much attention to them. Although I sometimes consiously look for places where I could be rolling on the throttle more aggressively, but what happens at mid-turn comes fairly naturally. I revisit body position consciously every now and then to make sure I haven't reverted back to any old habits.

Thanks Captain Obvious. :-D Just like "about 10 heat cycles" and "30 school days" may also not be that accurate. From my original post in this thread: "From this experience my opinion is that unless you are a lot faster than me those tires can last 3 track days. Of course there are lots of variables." There's no point rid'n around on burnt up tires, but there's also no point in throwing perfectly tires and money in the dirt. Just learn to recognize when the tires are done before it causes you to crash. Use the same brand and model tire regularly so you can get to know how it reacts. Each track session or heat cycle, start out easy and work up to speed slowly, over about 3 laps, so if you've done one too many heat cycles, you'll get a friendly hint before crashing. Smooth throttle control and other good riding techniques are probably fairly important during those 3 laps. :-D

No matter how stable the bike is, their JOB is to ride the bike to its ragged edge of stability. So if the engineers or suspension tuners find a way to make the bike more stable, the rider will just ride it faster and take it to the edge of stability again. Aside from the waggling around under braking, we can also see some serious twitching especially on bumpy tracks, and rear wheel slides under power coming out of turns. They can and do adjust the suspensions to add stablity in these circumstances but then the riders just take it to the next level. I just watched the 2004 superbike review (ordered off netflix) and there were lots and lots of cases where one rider had a "moment" (rear wheel slide) coming out of a turn and it killed his momentum, allowing the rider following close behind to pass in the following straight as a result (I guess 2004 is before traction control). So there you have it, they have to run at the edge of stability to win, but if they go just a bit over, they lose. That's racing.

Yeah I really like this site too. I hope it gets more active in the future. I can't figure out how to embed a picture either. There's a button that says "insert image" but nothing happens when I click it.

I really like the pilot powers and have used them on the track a lot and on the street. Here's a pic of my pilot power after it lived through 4 straight track days: http://picasaweb.google.com/harnois.adam/V...636749624135650 The orange peel effect you speak of is visible in the picture. After 3.5 track days I noticed some serious problems with traction in right hand turns and had to slow down a lot. The track I was on is a clockwise track so more right hand turns. And you can also see in the pic the glossy band on the right edge which appeared at the same time all that sliding started. I was running 30psi. From this experience my opinion is that unless you are a lot faster than me those tires can last 3 track days. Of course there are lots of variables. I still have the tires on my bike now and ride them on the street and there's no problem. But obviously I'll put on a new pair before any more track days.

Another thing I noticed about the videos, is that the riders consistently reach maximum lean angle, or very close to it, almost immediately, way before the middle of the turn... in other words, quick flick. So they can't be trail braking all that heavily. If you compare it to the most severe cases of trail braking, like what they may do when overtaking in a braking battle, their normal technique and line obviously lies somewhere between that example of severe trail braking and the quick flick, but looks to me to be much closer to the quick flick. It's seems to me that the advantage of trailbraking, and the reason why it produces the fastest laps, is basically common knowledge in most forms of motor racing - cars, bikes, whatever - which is mainly a later braking point. But I do trust experienced coaches who say their students go faster when they use it a lot less.

As far as what senses are being used I think it is mostly visual. One reason I think this is because I can go into the same turn in different gears and it doesn't create any trouble for me in judging entry speed. You mention that you have trouble judging small differences in entry speed. Personally I think I and most other humans are not that good at "incrementally increasing" turn entry speeds. Whenever I consciously try to do this I end up having some sort of bad line and tense feeling. We just aren't that good at consciously making the very very small changes we need to make in order to slowly improve our speed. When we consciously try to step it up we inevitably make too big of a change. What works for me is to just go into the turns at 100% of my comfortable speed. We can always judge what is comfortable. So then how can I get any faster? Well because "comfortable" speed is always going up due to just practicing and focusing on the right things. So then there the question of what is the right thing to be focusing on. For me it is the "visual skills." I have recently been working on something which I think is related. I notice that I sometimes revert back to a sort of "reference point tunnel vision," where I look at the turn-in point until I get there, then I look at the apex until I get there, and then I finally look up out of the turn. I can repeat good laps doing this, but as soon as I remind myself to look much further through the turn and to "broaden my vision," I feel like I start going faster into the turns and getting on the throttle sooner and using up more of the track, and have a lot less of that "damn I could have been going faster" feeling that jrock mentioned. It makes sense because by broadening my vision I can now judge my speed and line and so forth all in reference to the "whole picture." Plus it is just more visual information for the human brain to do its "pattern matching" thing. By focusing on broadening my vision my turn entry speeds naturally go up, without me having to consciously force anything. And the riding gets more fun because I feel like I can *see* all sorts of new ways to go faster. Chapter 21 and 22 from Twist of the Wrist II is what spurred me on to this and it has been immensely useful. The term used there is "wide screen view" and then it goes on to describe the "two step." If you are Level 4 then you've no doubt already heard of this. I've only done Level 1. These techniques are also extremely useful when playing racing video games, and for me that has even been an interesting way to practice the vision broadening skill. Even when playing the games I have to consciously remind myself to do it otherwise I revert back to my old tunnel vision habits. I also remember reading about some study that showed that one of the differences between experienced street riders and new riders was that the experienced riders looked further ahead and used their peripheral vision more to assess the current position. On the track, it can be a challenge when looking really far ahead around the turn to "pay attention" to where I am at relative to the apex without actually pointing my eyeballs at it, but I expect it will get easier with practice.

But the major impact absorbing material in your helmet is Styrofoam, not fiberglass or plastic. These paragraphs from the previously linked article explain:

I recently watched the "2007 MotoGP Review" and "The Doctor, the Tornado, and the Kentucky Kid." That's like 6 hrs of motoGP related stuff. Thankfully they are available from netflix. From watching this stuff it is very obvious the guys at the front, Rossi, Hayden, Edwards, etc, they are all hanging off in pretty much classic superbikeschool style, butt and shoulders off the bike equally, shoulders really low, and sometimes they are hanging off quite a lot. It's better to watch videos, you can see it more clearly. It's like the other poster said, Hayden is powering out of a turn in the picture you posted. And the rider in the chicane could easily still be at some point in his transition from left lean to right lean.

I remember seeing the fingers come off the lever and the throttle rolling on. And it seemed to happen a lot after the rumble strip/apex passed by in the background. But certainly I agree there is limited context and easily misinterpreted. Here is an onboard lap of Laguna from MotoGP. http://www.youtube.com/watch?v=iFGjfe0ita0 You can pretty clearly hear the throttle coming on mid-turn very consistently,except the first double apex and the corkscrew. So there is no trailing passed the apex as far as I can tell except where there's obvious explanations for it. Onboard with Rossi: http://www.youtube.com/watch?v=y0aE9tVyKYg Once again, based on the engine sound, I don't see any examples of trailing passed the apex except where there are obviuos explanations, not even in the first lap when there is likely some other riders close behind. More examples: Onbaord in Jerez: http://www.youtube.com/watch?v=IkLuqgrAo_4 mugello: http://www.youtube.com/watch?v=saRAvlipuMQ And so on, every track is probably on youtube somewhere. :-D

I don't agree at all with the idea that you have to crash in order to know how far you can lean. Obviously there are so many constantly changing variables ... tire model, tire temp, tire wear, track temp, track cleanliness, pavement type/texture, suspension settings, suspension oil temp, body position, rider inputs, on and on and on. To have to do this lean 'till you low-side experiment for each combination of variables would be very expensive and probably painful and you could never remember all the answers anyway. My philosophy on this is to do everything GRADUALLY. If you GRADUALLY roll-on the throttle coming out of the turn, then the worst that is likely to happen is your rear tire will slide just a little and it won't be that scary and you can back off before it gets out of hand. If you whack the throttle open all the sudden at a low lean angle then you are very likely going to crash. If you don't have any sliding at all then you might think, hmm, I could gain more speed there if I roll on a bit heavier, which is true, just increaese the roll-on very very GRADUALLY from lap to lap so that you don't ever SUDDENLY go WAY over the limit. If you come out of pit lane and do one lap nice 'n easy, 2nd lap a little faster, and 3rd lap maybe is full speed, GRADUALLY coming up to speed, then if your tires have been through one-to-many heat cycles you'll figure that out in a nice easy way somewhere in the 2nd lap. If you GRADUALLY over the course of many track days increase your speed then once again you will be given some friendly hints that you are getting close the limit in certain situations in the form of some gentle sliding, rather than having to crash. In about maybe 50 track days all on the same track (VIR North Course) my lap times have gone from about 2:05 to 1:45. That means I can now do 6 laps in the same amount of time it used to take me to do 5. (The pros can do 6 laps in the time it currently takes me to do 5.) Never at any point did I feel that i was "pushing" it to a point of feeling uncomfortable. I just kept practicing and concentrating on the skills and naturally ended up GRADUALLY going faster. Only recently I occasionally had some moments where I felt some sliding, mostly when the tires had come to the end of their usable track life. When the sliding did happen though it was surprising to me that it wasn't scary. I specifically remember one incident in turn 1 lap 2 after 3.5 track days on the same rear tire. The rear just slid out under throttle and I musta flattened out my throttle roll on and it came back in totally smooth and probably nobody other than me even knew about it. The rear tire was toast, but because I was gradually coming up to speed in that session, and was gradually rolling on the throttle, I was made aware of the situation with no drama. When a rider starts to push it to the point of feeling uncomfortable, that's when the big unpredictable scary slides/crashing happen. The other thing I've noticed is, that sometimes I get caught up in trying to drag my knee more and lean lower, and then I remind myself to look ahead for the reference points and concentrate on actual cornering speed and throttle control, and whenever I do that, what d'ya know I end up leaning lower and dragging my knee more and no doubt going faster.

Another thing to consider when it comes to evaluating the balance between trail-braking vs. the quick flick for a given turn is dips and rises. For example, the only track I've ever been on so far is VIR North Course. The only turn that I sometimes have a little fun with trail-braking is turn 7, which is the right-hander that starts up the hill after going under the bridge. The dip that starts up the hill adds so much mid-turn traction that the more elliptical trail-braking line works really well. Whereas the more constant-radius quick-flick line fails to take advantage of the added traction provided by that dip. The last part of this turn is an off-camber rise - a popular spot for high-sides - so a straighter exit line is useful here as well, further encouraging the more elliptical line overall for this particular turn. Due to the dip and rise and camber changes it is also a really fun turn! I need to get out to more tracks!

Watching MotoGP races, especially when they have cameras pointed straight at some of the riders' throttle hands, it does seem that they are braking beyond the apex in a lot of the turns, even when there is no one threatening to overtake. I've been curious to know why that is. I don't look at it as some technique to adapt to my own riding, but rather I am just curious to know why they are doing it. The only thing that makes sense to me so far is that it has something to do with the particulars of the turn or turn sequence in which they are doing it, as in the double apex example. But, it just seemed like it was being done in too many of the turns to be explained entirely by this. I can see how it could be shown mathematically or demonstrated that really good trail braking by the top top guys was faster in most turns UP TO THE APEX, but not beyond the apex. I am also curious about the 10 to 12 psi in the MotoGP tires. Anyone know of any articles out there on the internet that explain what is different about the tires that allows them to run those kinds of pressures? I tried searching but so far haven't found anything.

Seems to me forks are all the same story, except that perhaps we have the option of making a minor adjustment to the oil level to effectively create a more progressive spring rate. Forks are also designed so that they can hit the bottom out stop before the spring itself bottoms out. If the air in the forks becomes so compressed that it effectively becomes the bottom out stop, then some joker put too much oil in there.

Now we are definitely barking up the same tree. Right, "from top out." If we crank down the preload it is "harder" in that it will take more force to move the suspension off the top out stop and it will sag less under a given amount of weight. So what I'm say'n is that since we do not spend the majority of our riding time topped out, it is not very useful to think of preload adjustment as making anything "harder" or "softer." As long as our suspension is floating freely, not topped out or bottomed out, as it should be most of the time, we are not going to make the suspension feel harder or softer by mess'n with preload. Preload will just make it float closer to top out or closer to bottom out. It's more useful IMO to think of the preload as nothing more than a sag adjustment. Although we do of course have to keep in mind that adjusting sag may have some effects on geometry. Before I ever opened this thread I realized I could possibly solve the wiggle by cranking down on front preload. I might have even tried it while at the track - not sure, can't remember. If I did try it, it didn't work. And I also knew that cranking down on the prelaod was going to make the front end of the bike sit higher all the time, which theoretically would slow down the steering, hense "at the expense of geometry." However I'm not sure I thought about how going to stiffer front springs would get me less brake dive and still keep the better steering geometry.