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Dylan Code

Superbike School Riding Coach
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Everything posted by Dylan Code

  1. How Much Weight On The Seat?

    Most discussions of steering and "weight shift", "loading" and "helps it to steer" are riddled with illogic, and the people discussing will not reach a conclusion predicated on so many errors in thought. Rather, going to the basics of logic is the best way forward lest they get entangled permanently in confusions. Forums have become a popular platform to air ones flawed thought process, while other visitors try in vain to overhaul their whole logical approach to problem solving. Not saying I've got logic down myself, but some statements and articles have so many flaws, it's like: "where do we start?..." and just skip it. Remember when you have contrary facts, one or both are false. Some things to consider: https://en.wikipedia.org/wiki/Consistency https://en.wikipedia.org/wiki/Validity
  2. How Much Weight On The Seat?

    Well I think you've read enough data here and there to have plenty of food for thought. Really the rest is up to you to experiment with. It seems to me that a person like you is all about the journey vs the destination so enjoy your journey!
  3. How Much Weight On The Seat?

    The section of the bike that the seat is connected to is also the one with the pegs. If you put weight on one versus the other, the bike can't tell any difference. You still weigh the same as far as the bike is concerned. Try sitting on the seat as that's what it's for. We know racers don't hover over the seat while cornering, and even if they did, the bike would not know any difference. You said you wanted to understand bike dynamics more. So start with steering and read the article. Also the wiki article on countersteering: https://en.wikipedia.org/wiki/Countersteering
  4. How Much Weight On The Seat?

    You sound hurt... Anyway what I'm saying is that your approach is flawed and there may be some fundamental flaw in your research process. Looking over some basics on logic and the scientific method may help. Not saying I have those subjects covered, but I see a lot of circular conversations coming up with no resolution. Fully understanding something as complex as motorcycle dynamics is not possible with today's depth of understanding of the physics and mechanics. We can't even easily explain how a bicycle steers with math: https://www.scientificamerican.com/article/the-bicycle-problem-that-nearly-broke-mathematics/ Maybe you should start with steering if you want to understand these topics; read the article. The other thing you have to realize is that this all must help you get through a corner better. Maybe you don't need to know exactly how a brain works in order to think...
  5. How Much Weight On The Seat?

    It seems like you are trying to take everything you have heard on the subject and get them all to agree. Or maybe just stimulate an interesting dialog. Judging by your response it seems like this could be a circular conversation for some time, but if you really do want to actually know, I'd suggest you do some more of your own experiments, but read the definition of "confirmation bias" each time before you do any of the experiments. Also, remember that if you have contrary facts, it means that one or both are false. noun: confirmation bias the tendency to interpret new evidence as confirmation of one's existing beliefs or theories.
  6. How Much Weight On The Seat?

    Peg weighting is pretty much a joke among physicists. If you put weight on the peg versus the seat, does the shock know any difference? Does the contact patch know any difference? If you are in a row boat and press down on the bottom of the boat, does it sink further into the water? If you sit in a car seat and push on the dashboard, does it move the car forward? How effective is putting weight on the pegs? Have a look at the video:
  7. Steering Video No Bs Bike

    That the surfaces the bike was rolling across were not completely flat, coupled with a profiled tire, would be a big clue. Add to that what happens with front tire friction when a bike is leaned over and what that in turn does to the bars and you have more clues.
  8. Steering Video No Bs Bike

    Any of them. Just see the Off-Track coach for the day and schedule a time to ride it.
  9. Limitations of CSS techniques?

    Simon possibly thinks he knows what CSS teaches but only has former students' information about CSS to try and glean what is taught. That's the dictionary definition of the word hearsay. He never did any of our schools. Often these students who hop around to different trainers misunderstand pretty much anything they are told and then give each subsequent trainer a foul impression of other trainers who came before them. The biggest problem/confusion is that there is not one. Simon says to turn with the throttle off, Keith says to get the throttle on when the steering is completed. Those two are the same thing. Now to take up your points on anti-squat and "better" steering geometry. It appears that your surface understanding of a truly complex subject of motorcycle geometry will only get you tangled up in a ball of yarn unless you seek to further educate yourself--outside motorcycle forums. Your biggest clue would be to seek out what "trail" is and what "normal trail" is and what happens to it when the front brake is applied, and seek to differentiate between "turning", "leaning" and "carving an arc". Also what an increase in trail mid turn would do for a motorcycle.
  10. Here's a short TV spot about CSS. Courtesy of Superbike Planet
  11. S1000RR Rear Suspension

    The slip % should be between 5% and 15%, which it is, and the traction control will keep it in that range. It looks like you are getting a lot of slip % at steep lean, which would suggest that your entry speeds are a little low for your liking and are being compensated for with somewhat aggressive throttle while leaned over far mid turn. I have no clue about Michelins, but would follow the suggestions of the local distributor for that tire.
  12. New Schuberth lid

    I call BS on that link. Schuberth has been in the head protection business for 70 years. Practically, there is no effective way to test a helmet for all types of impacts. What's good for a light impact is bad for a heavy one and vice versa. Anyone's testing system is going to be seriously flawed regardless of how you do it. Current SNELL and DOT regulations are also criticized heavily on their outdated testing criteria. The same could be said for ECE or this UK government site. Schuberth makes helmets for bomb defusal, cars, motorcycles, police, firemen, etc. and has been doing so for decades. Here's some serious criticism on their methods: A LEADING safety engineer from Birmingham University* has spoken out against the SHARP helmet rating scheme, believing the system should be scrapped following the results of a recent scientific study. Dr Nigel Mills, who has worked on helmet testing and design for 30 years, believes the European helmet testing system is flawed. During an intensive six-month study, Dr Mills found areas of concern, which has prompted the scientist to ask for SHARP ratings to be scrapped. Dr Mills has pointed out three major factors within SHARP that are of serious concern. Speaking exclusively to Visordown earlier today, Dr Mills said: "First, the impact velocities in oblique impact tests must be realistic; gentle impacts used to determine helmet friction coefficients differ from more severe impacts in which the helmet starts to roll on the road. "Second, the test headform must simulate the human scalp and hair which allow significant helmet rotation. A test headform without scalp or hair responds differently and may overemphasise the friction of the helmet shell. The rotational acceleration of the test headform must be measured. "Third, the pass/fail criterion must be set. Only ballpark figures for human tolerance to rotational acceleration are known. You might imagine that independent researchers had agreed on the details, and the industry was convinced of the benefits of these radical new tests. However the SHARP scheme was developed by the government Transport Research Lab for the DfT without public debate." Dr. Mills criticises the oblique impacts in the SHARP scheme, as they don’t measure rotational head acceleration. Presumably to save money, they use a mechanics model, a friction coefficient and a direct impact test result to estimate the oblique impact performance. Mills’ study shows the model is too simple, so the estimated performance parameter (a linear head acceleration multiplied by a function of the friction coefficient) is meaningless. They weight test results from different sites in a complex way to estimate how many lives would be saved by a particular helmet design. This overemphasises test ‘results’ at the sides of the helmet, and totally ignores impacts on the chin bar region. Hence he concludes that the estimates are meaningless. Dr Mills feels that the British and European helmet standards could be amended to include tests for oblique impact protection, based on scientific consensus, with the design consequences considered.
  13. Can Quick Turn Be Overdone?

    Maybe there's more going on in this crash than meets the eye. Maybe there's a front end push/slip just when the steering was being initiated. I've not seen a quick turn bring the REAR tire off the ground ever, but that's what what looks like happened.
  14. Taiwan 2017

    Some photos from the Taiwan schools
  15. Steering Video No Bs Bike

    Cool story. Read this: https://www.scientificamerican.com/article/the-bicycle-problem-that-nearly-broke-mathematics/#
  16. Steering Video No Bs Bike

    The farther you get away for an object's center of mass, the more leverage you have. So lower bars would have less leverage. Also have a look at Newton's third law of motion and then decide what you mean by "load" and possibly rephrase.
  17. 16 Rr Race Prep

    I would get a K-Tech fork/shock combo http://www.ktechsuspension.com/race Or an Ohlins, both brands full forks and shocks, not rebuild.(expensive) On the motor, the "Power Kit" which consists of the full titanium exhaust, under $3,000, and an ECU flash from BMW, about $600. We can get a good price on the exhaust if your dealer can't give you a deal. Don't do an RCK 3 ECU unlock unless you are a computer techie nerd. If so, you'll be in total bliss. Beware of 3rd party ECU flashes. Some will be ok others, no. Tech support can be spotty from 3rd party companies. If you are nerdy and "know a guy" who you trust, go ahead. You can disable the ABS with the handlebar controls. I use the ABS "slick" mode. Works great for me. Get a datalogger and learn how to use it. I offer support on that to our students and people who get them from us or polite strangers.
  18. Short Video Tip On Body Position

    Hi all.This is a short video I did that you might find useful.
  19. Short Video Tip On Body Position

    Send your seat to a company called "HT Moto" and they will cut/shape the foam however you want it and re-wrap it with all sorts of covering options. http://www.htmoto.us/
  20. How Do You Read Traction?

    This is something I wrote a few years ago but never did anything with. Have a look: Placing trust in your tires is fine until they let go unexpectedly. Like a “friendly” cat that suddenly bites and claws your arm, you are always suspicious from that point forward. Sensing what the tires are doing and what sort of grip they are offering seems to be a question of experience and just getting enough miles in the saddle, but some riders come to our school with hundreds of thousands of miles under their belts, still lacking confidence in their ability to sense traction. Available traction can change all the time. What affects it? The list is long; here are just a few factors: tire compound, tire temperature, tire tread depth, tire pressure, surface temperature, road friction, road imperfections, changes in pavement and camber. Suspension, along with the changes one can make, is an art and science all on its own. You also have the biggest variable of all--the rider with his use of the controls along with his body position in relation to the bike. Trying to weigh these factors against each other during a ride is impossible so it’s more a question of feel versus mentally tracking an infinite number of variables. The clue to sensing traction lies in the fact that tires are always slipping when you corner. Car buffs know the subject of “slip angle” well. Slip angle refers to the difference between where the tires are pointed through a turn and your actual heading. For example, a driver turns his front wheels into a turn 13 degrees. If the car carved an exact 13 degree arc there would be zero slip angle. However what we actually see is the wheels turned in 13 degrees, but the car carving let’s say an 11 degree arc. The slip angle in this example would be 2 degrees. Motorcycles also have slip angle. My main point in bringing this up is simply to point out that the tires are always slipping a little when cornering and how much they are slipping gives us a clue on traction before the tires completely let go. Where it gets very different for a motorcyclist is when we consider the factor of lean angle against speed. We as riders have grown accustomed to expect a certain arc from the motorcycle when leaned in at a certain speed. When we get a departure from what the rider knows to expect, they should be suspicious of traction. Example: a rider leans their bike into a turn and finds it running slightly wider than what they would expect. The rider also notices that the bars have slightly less tension in them--they feel “light” in the hands. This would be a dead giveaway that the slip angle in that instance is greater than usual. Merrily leaning the bike over more could result in a total loss of traction. Incidentally, this is another reason we don’t want a death grip on the bars--it obscures one’s sense of traction by hiding the tension or lack thereof in the bars, another clue as to level of traction. If you know what to look for, your prediction of traction can improve. But again you have to know what to look for. Just like that cat that unexpectedly scratched your arm. You may not have noticed its tail whipping back and forth in a jerky, rhythmic pattern just before it pounced. This is perhaps an oversimplified view of a deeply technical subject but we have to start somewhere if we want improvement in our cornering. Again and as always, the track is the best place to work on your sense of traction and its other components such as speed, lean, line and surface.
  21. How Much Weight On The Seat?

    Sit in the seat, don't hover over it. There is no advantage from levitating over the seat unless you happen to be going over a severely bumpy section for a moment. The majority of your weight should be taken by the butt in the seat.
  22. Inside Foot Peg Weighting?

    Formally stated, Newton's third law is: For every action, there is an equal and opposite reaction. Press on a peg, it gives you the same amount back. Most bikes weigh considerably more than the rider so the harder one pushes down, the more the rider will tend to lift their body up. But think about it: if you sit on a bike and let your feet dangle, the suspension is going to sag under your body weight. If you stood on the pegs, the suspension would sag the same amount. Next time you ride, go straight with a loose grip on the bars and press hard on one peg and see if the bike changes direction. It won't.
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