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Hotfoot

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Posts posted by Hotfoot

  1. 21 minutes ago, Red_Baron said:

    New to all this, but Hotfoot and Cobie taught me the knee to corner and was one of the most helpful drill for me at  Las Vegas.

    Already signed up for April in Vegas and will test again my coaches patience. 😉 

     

    Glad to hear that, I look forward to seeing you there! I had fun riding with you in Vegas. :)

  2. 3 hours ago, yakaru said:

    Yep, we're about the same stature and I love the low displacement bikes as well so that's always useful! I've done knee over curb many times, for many reasons, but have always had trouble keeping my knee in my visual range due to my visor position. Tank over curb sounds like an interesting modification of it to try though, thanks @Hotfoot.

    FWIW, I don't try to see the tank in my peripheral vision ( I probably can on the BMW, but not on my little bike), but my outside arm is on it so I have a very good sense of where it is without having to see it.

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  3. One drill we commonly use in Level 4 is "knee over curb". The idea is to find a point of reference other than your head/eyes to use, to judge distance to the inside edge of the corner. If you approach the corner with the idea that you are going to try to put your knee over the curb instead of positioning your head over it, you can see (looking at your photo) that your tires would be at least a foot closer to the inside, probably more. Another advantage of using your knee as your reference is that most riders can SEE their knee in their peripheral vision, which helps to judge position over the curb.

    Having said that, I personally am pretty short so my knee doesn't stick out very far (so it is harder to see) and my knee position is not super consistent because on my small, lightweight low HP racebike I sometimes keep my knee tucked in for faster corners to reduce wind drag and/or lock on more solidly. So, per a suggestion from my Level 4 consultant, I started using the gas tank as my reference. I try to put the gas tank over the curb.  It helps mainly because I can know with CERTAINTY that when I am leaned over, I can safely get the tank over the curb without worrying about hitting it (or the dirt, or ragged edge of track) that I DON'T want to hit at full lean. It gets me a lot closer without having any attention on worrying about hitting the curb. Since your height is, I think, similar to mine and I know you sometimes ride a lightweight bike, using the tank might be something to try.

     

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  4. Good gracious, what a story. I spent in summer in Wisconsin and couldn't believe the number of deer there and they certainly can jump out very suddenly. Sounds like you have a good plan for really serious protective gear for future, which is great.... but is there a way you can find a place to do some track riding, where conditions are a little more controlled? Local track days, or riding schools? 

    Have you ever considered getting into a mini-moto or super-moto bike that you could ride at local go-kart tracks? They really are a lot of fun and you can ride at a high level (performance wise) at relatively low speed, and there's a whole lot less chance of a deer leaping out at you. It is inexpensive and it can be pretty easy to get a group of buddies to go with, which makes it even more fun.

  5. 14 minutes ago, Jaybird180 said:

    If it were practical, the rider could stiffen during braking then relax when making the steering input.

    Ah, this makes more sense, now I'm with ya.

    Yes, that is EXACTLY what a rider would have to do, if they were not strong enough to get a good lock on with the lower body, and not strong enough to support their upper body with their core muscles, they would be forced to use their arms to support themselves under straight line braking, then do their best to get off the bars when it is time to steer. What else could one do, other than trying to add tank grip or other anchoring devices to make it easier to lock on to the bike? 

  6. 8 minutes ago, Jaybird180 said:

    I think you're saying that the rider has the ability to change the fulcrum of the point of rotation and that this action of having more mass further from the fulcrum creates more inertia for fork compression. As kinematic theory I believe it would produce the desired conclusion.

    I believe that it fails in practice because (taking the extreme example) your rider can't alter her mass to be centered in her head anymore than she can focus it at her feet.

     

    A rider cannot change the location of the COM within their body, no. However they CAN change the position of their body. Do we agree that when a rider hangs off the inside of the bike, their COM is moved farther to the inside of the corner?

  7. 14 minutes ago, Jaybird180 said:

     

    For the purposes of this discussion, can we leave handling issues aside? 

    What IS the purpose of the discussion, if you are not interested in handling issues?

    If this is a purely theoretical discussion and not directly related to real world riding, this is probably not the right forum for that sort of discussion.

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  8. Do we agree that if a rider sits up high, that the rider's COM is higher than that of the bike, producing a rotational "moment" that wants to make the bike rotate around the front tire's contact patch and create a "stoppie"?

    If we agree on this point, then the remaining questions is: does that situation cause more fork compression? My thinking is that yes, it would, because the "moment" created is a new force, in addition to the normal braking/deceleration force from mass of bike & rider. (The farther apart vertically the COM are, the bigger that "moment" becomes.) That rotational force, which centers around the front tire contact patch, can be resolved into two components, where the rider connects to the handlebars: a forward force and a downward force. It is that additional downward force that puts a new vertical load on the bars and THAT is what I think causes more fork compression.

    If the rider sits very low on the bike, and braces forward (instead of down) with his/her arms, I do not know if there would be any additional fork compression. My guess is that there would not be.  However handling would still be negatively affected simply because the pressure on the bars restricts handlebar movement and if there are any imperfections in the road, the bars cannot move as they need to, to compensate. And obviously if the rider is entering a corner it is much more difficult to make a precise steering input when one's weight is on the bars.

    The reality on an S1000rr is that they have unbelievable stopping power, and at maximum braking it is quite difficult to hold on well enough with your lower body to have zero pressure on the bars, especially on a hard braking track over the course of a long race. That said, when would it be MOST important for rider to be light on the bars? During straight line braking or when entering a corner? When is the best time to get the hardest braking done, straight up or leaned over? If a rider does have some pressure on the bars during hardest braking, is it better to be sitting straight upright, or to be down low? Is it better for any bar pressure to be forward on the bars, or downwards? 

    • Like 1
  9. Oh, now I understand your question and see why you are asking. Yes the front tire has to stop the mass of the bike and rider. The total mass (and thus the braking force required to stop it) doesn't change. However, the location of the rider's center of mass CAN change, and if the riders C.O.M. is significantly higher than the bike's center of mass, that introduces a new element, which is the lever action of the rider's upper body. That introduces a "moment", which is a rotational force, which acts (if the rider is bracing on the bars and using the bars to hold up the upper body during braking) directly on the handlebars and thus the forks.

    We can talk about the theory of it but really It is very easy for you to go test this - put a zip tie on the front fork of your bike, tight enough to stay in place but not so tight that it cannot be moved at all. Slide it up to the top. Set or choose braking markers so you can be consistent in braking distance, and go out and brake hard in a straight line, riding with your knees tightly locked to the tank, your chest low on bike, and keep your arms loose.

    Measure or photograph how far the zip tie got pushed down. 

    Then go back out and do the same braking run with the same approach speed*, but this time sit up tall and lock your arms, don't lock your legs or support your body with your core muscles, let the handlebars do all the work of keeping your upper body from tipping forward. See if the fork travel is different. *NOTE - wear all your gear and be careful doing this, it IS possible to get into a "stoppie" or create a front tire slide, the weight on the bars and the restriction on the bars can really change the handling under braking. You may want to do a few initial runs at a lower braking intensity to get a sense of what will happen. 

    If the front end is not super stiff (spring weight too high for the rider, or compression damping way too high, or forks bound) you should see a measurable difference in fork travel between one riding position and the other. 

    Or, even better you can come to a school and ride our Braking Bike, which has outriggers to help stabilize the bike in case of a front end tuck or slide, and try both ways and see how it impacts the bike behavior and your ability to retain control under heavy braking.

     

    • Like 1
  10. On 10/22/2020 at 6:31 PM, Jaybird180 said:

    Has the rider’s mass been altered? Please, no suppositions about the squid who misses the braking point and involuntarily alters his suit’s mass. 😂

    No the rider's mass clearly doesn't change. However, we know the braking is causing a force on the rider. Where is the rider attaching to the bike in each scenario? Where does the force get transmitted to the bike, if the rider locks his arms arms and uses his hands to stay on the bike? What about if he uses his knees instead? How does the change the effect on the bike, on the forks?

    Hint: consider the location of the bike's center of mass, and how close or far away the rider's attachment point is from that, in each scenario.   

    • Like 1
  11. The best pressure setting can vary by bike/rider weight, by track, and by temperature and is not always the easiest thing to figure out. Best thing to do (assuming you are talking about track riding) is to ask the Pirelli race tire distributor, and be specific about what bike you have, what pace you ride (A, B or C group at local trackdays, for example, or tell them your typical laptimes), and whether it is expected to be cold or hot out. 

    The Pirelli range given above is a good starting point; if you see any abnormal tire wear (tearing, or uneven wear) occurring, you can ask a tire provider or suspension person for guidance, or if you want to look into it yourself, Google Dave Moss, he has lots of videos about tire wear and suspension that can help you "read" the tire to try to figure out what is happening.

    If none of that is available, as a rough guide try starting out around 30-31 psi cold (which should go up to around 33-34 hot) on the front, and if the ride feels harsh or the tire doesn't seem to grip as well as you'd like (especially over rough pavement), try 1-2 PSI lower and see if that helps. If the front feels mushy and sluggish to steer, try going a few psi higher.  

    • Like 2
  12. 54 minutes ago, mugget said:

    Great to hear the Twist II video is available online! I loaned my DVD to a friend and he must have liked it because I still don’t have it back after years and years. I will definitely have a watch. 

    Good on the warmers, one less thing to worry about. 

    Yes, I was really happy for the Twist II movie to be available somewhere for instant streaming, I have the DVD... but no DVD player anymore! Now I can stream it on my phone from Amazon, so cool. 

    If you do watch it, post a review! It doesn't have many reviews yet since it just recently got put on Amazon.

  13. Sounds like you have a lot of things taking up a lot of your attention - new track, new body position, new leathers, new tires - so I agree with Yakaru, definitely take your time and give yourself a chance to get comfortable, let eh speed come when you are ready rather than trying to push for it. With less free attention available things will seem to happen much faster and that triggers SRs, such as tension, target fixation, choppy visuals, etc.

    Focusing on one drill at a time is a good plan - maybe devote a session (or more than one) to finding more reference points in the places you feel a little lost or rushed, and once you are better located on the track, spend a session focused on relaxing on the bars, etc.

    You mentioned switching to race slicks - are you using warmers? If you are not, race slicks can feel pretty unpredictable until they get fully warmed up and that could add to your distractions - if you aren't using warmers you may want to consider using them or going back to something more like a Q4 that has a wider operating temp range.

    Might be worth your while to review "A Twist of the Wrist II" video, also - is is finally available for instant viewing on Amazon Video (yay!!!), here is the link:

    https://www.amazon.com/gp/video/detail/B089ZNVBW9/ref=atv_dp_share_cu_r

    It could help you work out which drills and skills you want to focus on most, on your next ride.

  14. On 9/7/2020 at 7:22 PM, slylos said:

    Excellent - I will look these up. Is it safe to say that I can use my knee as a lean angle gauge and if I touch and am still running wide that I've just got too much speed for the corner? 

    You can use your knee as a lean angle gauge. If you are touching it and still running wide it probably does mean you have too much speed, but it doesn't necessarily mean that speed is the ONLY (or even the PRIMARY) problem, for you, in that corner. For example, if you had a bad line or poor body position that could contribute to excess lean angle and thus limit your possible speed through the corner. If you are running wide and you don't know why it is happening, it sounds to me (especially in light of your prior questions in this thread) that you are riding over your head and pushing too hard on corner entries. A better approach would be to slow the entry speed down a bit, get some training and build back up to the speed. 

    Getting to school would be the best option but if that is not practical, do you have the "A Twist of the Wrist II" DVD? It is worth watching that to look at lines, throttle control and visuals skills, to find out causes for running wide. (If you don't have the DVD, it is also available for rent on Amazon Video.)

    Question for you - if a rider were to turn in early for a corner, and/or steer the bike slowly, what would happen to the rider's line, and what would the rider have to do to correct it?

  15. This is actually a tough question to answer because it can depend on a LOT of variables (pressures, temps, suspension settings, tire fit to bike, riding style, etc.) and that is probably why you haven't seen much response. It does look like cold tear and it's interesting that it seems to be happening near where the tire changes from one compound (harder) to another (softer). Do you accelerate hard, in short bursts, with minimal lean angle? What is the tire size you are running, is it the same size as the OEM, or have you put on a wider tire? 

    I agree with Yakaru that you should probably start with lower pressure in that rear tire, it does sound too high, and next I would pay attention to your throttle control - when do you begin your roll on and do you roll on smoothly and gradually or quickly and hard?

    My first guess (aside from the pressure being too high) is your throttle application may be a bit too late and too abrupt, a "point and shoot" type of riding, which means nearly all of the acceleration occurs somewhat suddenly as the bike is mostly upright, putting a lot of load on the area where you see the tearing, but not giving the tire much time to warm up with gentler acceleration at steeper lean angles. It might be a good idea to review the Throttle Control info in Twist II or on the Twist II DVD, then experiment with your throttle control in corners and see if that reduces the tearing.

    • Like 1
  16. Based on your email above, I'd say go for a 2 day camp. More time with your coach, fewer riders on track, and a busy schedule with LOTS of riding time.

    At either a 2 day camp or 1 day school you will always be allowed to ride at your own pace, and not required to wait for other riders or adjust your pace to others (except in the very first couple of laps of the day which are sighting laps so you can get a look at the track, where the flags are located, etc.)

    Full disclosure, just so you know what to expect, even on a 2 day camp the morning of the first day can feel a little slow, due to registration, getting people suited up, first classroom, and first ride rotation (especially if you aren't in the first group out), however once things really get rolling you go into a track/classroom rotation that goes fast and gets you tons and tons of track time.

    I've done schools similar to what you describe above, waiting in line to do each exercise or having to ride in groups with no passing, etc., it definitely can strain your patience especially if you are a real enthusiast with a higher skill level... the CSS experience is much different and I have no doubt that you will have a blast.

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