Jump to content

jcw

Members
  • Posts

    28
  • Joined

  • Last visited

  • Days Won

    5

Posts posted by jcw

  1. OP, I see where you are coming from.

    David Moss has this mantra I've been seeing on his facebook videos- brake- throttle- turn. And it confused me at first. Unless you think of it as maintenance throttle rather than actually accelerating. Still, even then I'm confused a little.

    My impression of TOTW and reading here is that you simply don't want to get into the habit of accelerating and adding lean angle Even if at your speed and skill level you are far from the limit of the tire. As you get faster, it's simply too easy to shoot right past the warning signs of approaching the limit.

    At the same time you want that throttle control where you are gradually rolling on the throttle while trading off lean angle. Ideally you want to set up your corner so you can accomplish this. Obviously, it's not always possible on the street.

    At least that's my take...

     

    I mean when you are really lapping around a track and feeling fast and you set up the corner right and make your pivot steering input, I can't imagine rolling on the throttle at that time as well. It seems like too much is going on with the chassis much like you don't want to be moving around in your seat at this time either.

    Once you release the inside bar pressure, settle down in the seat, then I can see rolling on maintenance throttle. Then it's a gradual roll on the throttle while coming out of your lean.

    • Thanks 1
  2. I'll check back in after my next trackday.

    Follow up---

    Trackday was almost washed out. I got in 1 good session and a wet one and just called it a day...

    I was only able to work on one thing and that was really focusing on getting a good base with the outside leg to pivot steer with the inside arm. And man was it effective! I was able to notice improved steering input speed/force(whichever is correct) and accuracy even after that one dry session.

    One of the side effects, though, was that I ended up more centered on the bike by mid corner and wasn't "hanging off" as much meaning I think I was carrying more lean angle. (my tires were more clean to the edge after my only dry session)

    I did a bad thing and played with the triple offset reducing it 1mm before the trackday as well. The difference was immediately noticeable and I let myself have several street riding days to get used to it before the trackday.

    I did also work on getting on the throttle as soon as I released countersteering pressure on the bars. And then focus on when I could trade lean for throttle. Found out this really mean using your vision effectively to pick out the correct exit line that lets you do this.

    After the trackday, I happened to read something on early apexing that made so much sense. Beginners like me will tend to turn in early thinking it's the safer line. You might even rush a corner with more entry speed because you think it's safer. But all it does is run you out of corner on the exit. It really made sense to me WHY i was having those pucker moments when I find myself on a line that was going to be too wide on exit.
     

  3. Yes, I've crashed three times in one and a half years and the second one fractured my clavicle. Good thing I'm stupid and stubborn and I keep coming back for more. But I've almost got a decent degree of confidence back. Traction concerns are more imagined than real, I think. One crash was my first time on a soaking wet track and I was on DOT supercorsas, another me and another bike decided to occupy the same space at the same time going into a corner. My fault. My confidence was sapped for a while.

    No concerns with clearance. I've set up the bike with some good rearsets and the bike can lean farther than I dare. I'm nowhere close to dragging a foot or a knee for that matter. Here's a random pic of me on my first trackday this year. I don't think I've progressed much from this.

    autobahn.jpg.7df32a7b57a69ce5fe1caa0f75a05db4.jpg

     

    20.jpg

     

    I think I know how much lean I need, it's the effort to turn that seems excessive. But at the same time, I know I'm your typical not-so-serious beginner/intermediate trackrider and know I'm not REALLY hitting a deep apex.

     

    Right, so to stop leaning, you ease up on the countersteering pressure at the bars. The steering should fall in line and then follow the corner.

     

    Vision is something I always need to remind myself to maintain. Even though I've ridden this track for last 8 years (usually only once a year until last couple), I haven't really been serious about going fast until last 2 years.

     

    I struggle with getting on the throttle early enough. So, I think I'm for sure done with steering before getting back on the gas. It's another thing I'm working on.

     

    Thanks for the directions, I'm seeing what I may need to work on and will figure a plan of attack for my next trackday in a couple weeks.

  4. Right, so ive been working on my body position not to hang off so much but positioning myself to make effective input for countersteering at the bars.

    Ive read about the technique of pushing the inside bar and bracing with the opposite (outside) leg. And the wall example. I need to remember to do this more as i believe i tend to steer with both hands and from both feet or my butt.

    Hopefully this will make the difference when i get back to the track this time.

     

    The pulling the bike down to the apex might be my residual desire to body steer the bike into the lean which obviously is not doing the job...

  5. Thanks for the reply.

    I have not done the school yet and know of some of the drills through second hand descriptions only. I have used the hook turn technique as i understand it and do see the usefulness of it.

     

    I take T1 on a neutral throttle slowing a bit, i know the really fast guys are just flying through here using engine braking only. Ive definitely slowed down on brakes before this. But its the fastest "turn" im negotiating.

    T3, just coming off throttle after accelerating down the short chute.

    I have trouble pulling the bike down to the apex is probably the best description i feel. Maybe its my fear or inability to lean the bike far enough when going fast(er).

     

    I go back in two weeks and wanted to have something to try. I asked a coach and they told me to take it in a higher gear.

    But, good to know that for a simple corner the best way around is gradually trading lean angle with braking. How does this apply to the quick turn or quick flip turns?

  6. At a recent trackday, one of the coaches was leading a classroom session and was describing the bikes "attitude" on and off throttle.

    My impression of what he was saying was that the bike is always slightly pitched back on acceleration or pitched forward off throttle or on the brakes. And your goal is to minimize coasting.

     

    So, it got me to thinking about the timing of steering input and this chassis attitude. I know that weight shift forward will change your geometry to decrease rake and trail and possibly make it easier to get the bike turned. My question is, is this the goal in every corner? How much effect does this on/off throttle exactly have on that initial steering? Do you look to pitch the bike forward slightly and time your steering input during this time to get the most response from the steering input? Obviously you aren't going to jam on the brakes and countersteer your hardest.

     

    I was noticing significant resistance to turning going into a couple corners at my last trackday. Turn 1 at autobahn cc north is a short left kink after the front straight where I make about 125mph and at T3 after a short short straight at about 75? I've made changes to my body position since that last trackday, getting closer on the tank when practicing on the street but have yet to try it out on track. Just with this simple experimentation it is obvious that a higher center of gravity noticeably slows your ability to lean and transition the bike. It has not been as clear to me whether timing the countersteering input with weight shift forward is as helpful but this is on the street where I'm building in a much greater safety margin.

     

    I ride a 11 gsxr750 with shimmed rear shock. And I have the ability to play with the fork offset if needed. I was thinking about this but wanting input on whether I could improve turn in with riding technique before I further mess with the chassis settings.

  7. On 4/25/2018 at 12:19 PM, Jaybird180 said:

    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.

    • Like 1
  8. 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.

    • Like 1
  9. 10 hours ago, Jaybird180 said:

    ...But I keep at it; I keep trying to sort through to find usable morsels of truth, what I can use and what might be better reserved for another time. It's a double-edged sword trait.

    I'm grateful for all of it.

    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.

    • Like 1
  10. 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.

    • Like 2
  11. 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.

  12. 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...

  13. 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...

  14. 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

  15. 5 hours ago, ausrobbo said:

    If you read through the article I posted a link to, it concludes that wider tires primarily are for wear reasons.  As we all know, a rubber tire sacrifices itself to provide the friction (all the gum balls on your front tire after a track session prove this is so).  A small tire dealing with significant friction demands, and in drag racing probably being overloaded will wear fast.  So if you had the smallest tires that could support the weight of the car and did a run, you would likely destroy them due to friction heat and mechanical stress.  If you were really serious about winning a drag, you could have single pass tires that had just enough strength for a run and then die.  They would be smaller and lighter.  But you would change tires every single pass.  So the extra rubber is for wear and handling of forces - vertical, lateral, roll on the sidewalls/carcass, flex to absorb acceleration and deceleration shock, bumps and so on.  It doesn't provide more friction or grip.

    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.

    • Like 2
  16. 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.

    • Like 1
  17. 1 hour ago, Jaybird180 said:

    When you hang off and push the bike up at corner exit getting hard on the gas...some people actually believe they can push the bike up! Maybe you can if you were in your knee the whole time as you'd have something to push against. 

     

    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...

    • Like 2
  18. 31 minutes ago, Jaybird180 said:

    Is it possible that the change in position results in better leverage at your elbows being transmitted into the bars?

    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.

  19. 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.

    • Like 1
×
×
  • Create New...