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Everything posted by jcw

  1. jcw

    Can Weight Shift Theory be debunked?

    What a coincidence! This popped into my mind as well just this past week. And I was ruminating on it as well... Roll and Yaw are two distinct types of motion on the motorcycle. Most people think of roll (lean angle) when we think of cornering. But, what we are really looking for is yaw- getting the motorcycle to go around a turn. Because of the way our physical universe exists, the most efficient (perhaps only) way to achieve this yaw results in roll. Do you lean to turn or do you turn to lean. LOL. Anyway, I found this interesting technical, analytical real world article measuring this yaw and roll and various rider inputs here. http://bicycle.tudelft.nl/schwab/Bicycle/evertse2010riderMinApp.pdf I had to read it a couple times and only understand part of it, but it clearly shows the countersteering inputs applied in getting the motorcycle into a turn, the yaw rates and direction, the roll rates and direction, the steering torque and direction and the actual steering direction. It goes into gyroscopic moment (which might be what your original question was referring too) and how that initial countersteering input can itself contribute to the roll but minimally. Fascinating stuff.
  2. jcw

    How Much Weight On The Seat?

    On a more practical note, 60 degree weather here was a nice change of pace. another hour or so of riding a loop that I use to practice, I find myself getting comfortable after crashing last year a couple times at the track and recovering from injury (broken clavicle). i focused on a stable strong body position (one cheek off, torso hips open slightly) to make my countersteering input (getting low on the tank helps me to push out not down). Then, as I enter the turn heading to the apex, I slowly drop my elbow and head into position as I clip the “apex.” Remembering to pick up the throttle as soon as i can see my exit point. The faster and wider my vision is, the earlier I can apply the throttle. For me, it takes a conscious effort to sit my backside down through the corner but I find that sitting back a bit with about that fist between me and the tank helped me relax and ride the bike rather than “fight” it.
  3. jcw

    How Much Weight On The Seat?

    That’s all I’m trying to do, too. but all this talk of logic and reasoning is giving me a headache. let me ask you something. how does one know who is right and who is wrong? If mathematics cannot fully explain the way a motorcycle steers, what makes someone so sure they are right and others are wrong? I agree that much of the internet is a big wasteland of misinformation. I am a professional by training and (like, you) spent some considerable time in secondary education after high school (13years for me, yikes!). I am not unfamiliar with textbooks and classroom and learning. Last 5 years were in hands on training learning my craft, I am not unfamiliar with the physical aspect of acquiring new skills. While I would no sooner tell someone to go to any internet forum for information I trained in, I realize that if carefully selected, there IS a place to look for this information. I am also grateful for any information I can glean. Just wish it wasn’t so shrouded in mystery sometimes.
  4. jcw

    How Much Weight On The Seat?

    Thank you SO MUCH for your help. I'd rather be naturally fast than stubbornly, studiously slow, but it is what it is. Rather I think it's the way I learn. I've always been a watch and watch and watch then copy. Not so much good at working it out myself on the fly.
  5. jcw

    How Much Weight On The Seat?

    That’s ironic you link the wiki article. I have read it. they describe countersteering by weight shifting and being able to initiate turns by making the bike lean right or left through peg weighting. You may not change the center of mass very much, but the fact that bike is now leaned, it induces the front wheel to swivel and create the countersteering input. ‘They point out that the movement is minor the heavier the vehicle is, but might this be what is best in the middle of a turn to hold a line if needed? its not that I don’t believe in countersteering, it obviously is the most effective way of getting to your lean angle quickly. I just wanted input on how much weight I should have on the seat vs crouching on the pegs. Now that you’ve made it somewhat clear, I can make my adjustments. i went out for a ride and found a nice feeling of stability cornering when firmly seated on the bike. And I was surprised at how much I was actually squatting on the pegs before and how hard it was to break the habit the faster I entered. I still felt like I wanted to be up on the pegs as it felt I was in better control of the bike, but I know this is not my goal. Maybe it’s a survival reaction, like I’m ready to jump off if I slide. Lol. my goal is to be in position before the corner. Enter the corner firmly seated in good position to apply the initial countersteering input. Get to my lean angle without moving my body position around to upset the bike. Then, pick up the apex and apply gradual throttle to settle the suspension, then the exit point, maybe at this point move the upper body or weight the outer peg or counter steer to get the bike up and out of the lean.
  6. jcw

    How Much Weight On The Seat?

    Nah, just trying to figure out how much weight to put on the seat... If I can understand a little more bike dynamics in the process, so much the better. It is warmer finally today. I'm going out after work and will experiment on a few things. If you have any suggestions pertaining to the above, it would be greatly appreciated.
  7. jcw

    How Much Weight On The Seat?

    I am slow (on the bike) and realize it. I am on the steep part of the learning curve and realize it. But I desire to go faster. There is no benefit for me to have this confirmation bias you speak of. My motivation is not to stimulate controversy. If I was at your school and you told me to stop riding the pegs and sit down I would. If you told me that at my level of learning it's best you keep your ass in the seat, i'd listen. And I am trying...
  8. jcw

    How Much Weight On The Seat?

    I have seen the video, yes! With all due respect to the vast wealth of knowledge here, I totally agree that as a static mass in steady state peg weighting has little (but not nothing) to do with changing the direction of the bike, however... That rider in the video in the first clip moved his center of mass(not that much either) and the bike moved. When he tried to turn it back to the right, although the bike did not go right, it straightened up. In the second clip he was VERY careful to keep his center of mass in line with the bike. I think the video demonstrates that YES, peg weighting does little, but does something (!) when you move the center of mass off the centerline. Physics says it must. Practically speaking, removing a heavy mufller off one side of the bike makes the bike feel different. Even in twist of the wrist 2 code and chandler mention several times, weighting the pegs and getting some weight off your backside allows your legs to absorb some of the suspension work your bike would normally have to deal with. I think of it as decoupling the two masses, the bike and you. And since one can greatly influence the weighting of a bike with body position, I think it can't be dismissed. I think of fast transitions, you are out of your seat moving from one side to the other. If you sit like a rock on top of the seat, I would imagine the effort to turn with pure countersteering input would more easily upset the bike. I realize this might be two different things, but I think they are related in control of the bike. The problem I see with it comes with using it too much entering the corner (or at all?). If you really de-couple your body and "push" you bike down and away, you are essentially riding at best crossed up. Totally incorrect and not how the fast riders these days do it. I guess that's the difference between motorcross and road racing. I understand not wanting to stress peg weighting (or better yet center of mass movement) because of several reasons. It's less effective, and puts you in an unstable and less advantageous position. Help me understand...
  9. jcw

    How Much Weight On The Seat?

    It's interesting how as you progress along in your riding, the same questions pop up. I'm experiencing the same issues as the OP. I find that weighting the pegs let's me countersteer the bike and get to lean quicker, but then I find myself sitting on the inside footpeg to maintain my line through a corner. I imagine I'm looking a little crossed up at the moment and this year am really trying to shift my weight more evenly over to the inside. In doing this I have experimented with sitting on the seat vs hovering over it. It is a much different feeling. Looking at the motogp boys (and the SS and superbike as well), I don't see how they can go from leg dangle with their weight on the seat to help rear traction while braking to all of a sudden, weighting the inside peg with most of their weight. I know peg weighting is not emphasized here but this is an interesting read. And opinions from racers. https://www.sportrider.com/art-science-body-steering-vs-counter-steering-part-two#page-15
  10. jcw

    Practicing BP - Feedback of proper BP welcomed !

    someone suggested to me a body positioning tip. It's essentially the same advice as above. But if you think armpit over gas cap, you'll have an extra cue to help remember to move that upper body over.
  11. jcw

    Lowering the body

    Drag racers rebuild their engines after each run. You really think cost is preventing them from running a skinny tire if they could gain a tenth? No. I have corresponded with the author of the article you link and while he might understand physics, I'm not convinced he understands motorcycle dynamics in a practical sense. The truth lies somewhere between the two. I have yet to find the answer. But the closest reasoning I've read that the coefficient of friction rather than being a constant can vary with temperature. Large contact patch might resist temperature change hence resist changes in coefficient of friction. Additionally, coefficient of friction does not accurately describe a rolling and cornering tire that operate with some slip angle. The tire is not stationary but not sliding either. No, it is too simplistic to say contact patch doesn't matter. From a practical motorcycling sense, much of Code's teaching talks about contact patch and friction. Based on all that practical experience of thousands of riders, there is some truth to the statement. Just my opinion.
  12. jcw

    Suzuka 8h GoPro helmet cam

    Anything this teach us? Suzuka is one of my favorite circuits.
  13. jcw

    These lines???- NJMP

    Thanks for the video. I love watching fast guys go round the track. I think the simple explanation is he is running well within his comfort level in traffic. Simply, the people he is passing at the first part of the video are not nearly as fast as he is. Watching him on clear track, he appears to be running faster and with a wider entry line when appropriate. (Not every corner entry dictates a wide line, not every corner exit dictates using every bit of track.) Entry corners and Exit corners are terms I've heard Ken Hill use in his podcasts. These may be common use terms. Printing a track out on paper and drawing out racing lines that make sense is a great way I've read to get an idea how to take a corner. Bring it to the track and make adjustments as you find you need. I think your question boils down to how does he continue to make corrections to his cornering line after he initiates his lean. (Not that it's ideal. You'd like your inputs to be made at corner entry and be done, right?) But I think the short answer to your question is Countersteering. (at least for me) staying loose on the bars is most important, locking in a secure lower body position on the bike so that you can make fine bar inputs, and assisting the corner lean with appropriate peg weighting (one of the hidden keys to the puzzle for me). I think CSS teaches outer peg weighting to assist locking the leg to the tank. I like it, but I've also found inner peg weighting and sliding your butt almost till it feels you're sitting on your calf really helps hold a tight line.
  14. jcw

    Against the flow

    I get the sensation of "pushing" the bike up as a countersteering input coming out of the corner. If you remain in your "hang off" position or even exaggerate it on corner exit with your upper body, you really have no recourse but to countersteer the bike back upright out of the lean. For me that movement of putting bar pressure on the outside hand ( and pulling with the inside hand) could be interpreted as "pushing" a bike up. It's not a subtle sensation. Sometimes you'll have to really "push/pull" to straighten the bike up to get ready for the next corner. Maybe you are essentially saying this...
  15. jcw

    Lowering the body

    Possibly... But the position is not much different. I admit I don't fully understand it. I mean the leg dangle guys don't mind sitting firmly on the seat on corner entry. But I'd bet on side to side transitions, when they need most bar input, they are light on the seat.
  16. jcw

    Against the flow

    Like stated above, if you run out of lean angle and drag hard parts, hanging off obviously helps. Short of that, hanging off might give you a small margin or error to add lean/countersteer if you can't make the corner. Way short of that, you probably should just be in a position as comfortable as possible to make your throttle and steering inputs. For me thats the traditional inside of midline with your outside leg locked on tank.
  17. jcw

    More Than One Method To Lock On? Level 3 Vs Pros.

    Sometimes I'll experiment wedging my foot in like Corser teaches in one of those videos. If i do it just right, I can even get the feeling of locking in with my feet.
  18. jcw

    Lowering the body

    For me, weighting the pegs makes the bike respond quicker to inputs. Instead of changing c of g, which physically is not possible by changing your attachment point, i think the benefit of weighting pegs has to do with removing your dead weight from the seat and allowing your own suspension (ankle, legs, hips) to take up some of the work of moving the bike. Decoupling your mass from the bikes mass to a small degree. It is noticeable and dramatic for me, cornering with your butt planted in the seat and cornering weighting the pegs.
  19. jcw

    TC Rule #2 and Braking

    This talk about speed of weight transfer on the front brakes has some real world relevance. If you look at the anti dive front suspensions from recent past, even BMW's duolever front suspension, when you take away fork dive blunting the abrupt weight transfer, the sudden loading of the front wheel can overwhelm traction. I've never ridden a bike with anti dive forks. I only have read about this limitation. Any first hand experiences?