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Dylan Code

Superbike School Riding Coach
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Everything posted by Dylan Code

  1. 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.
  2. 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 Current SNELL and DOT regulations are also criticized heavily on their outdated testing criteria.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.
  3. 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.
  4. Taiwan 2017

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

    Cool story. Read this: https://www.scientificamerican.com/article/the-bicycle-problem-that-nearly-broke-mathematics/#
  6. 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.
  7. 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.
  8. Short Video Tip On Body Position

    Hi all.This is a short video I did that you might find useful.
  9. 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/
  10. 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.
  11. 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.
  12. 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.
  13. Ktm 390

    The suspension is a bit bouncy so you can't flick them. Ride a 250 Ninja, try to get back to the gas as soon as possible, keep momentum up, entry speeds high, etc...
  14. Ktm 390

    Yes I rode it. I thought it would be more of a fun ride but I prefer the Ninja 250.
  15. Video Showing Where Rider Was Looking

    These are video clips of a rider wearing gaze tracking glasses while riding. The glasses track the movements of the pupils and is overlaid on video showing what the person is looking at. The circle moving in the frame indicates where the rider was looking. An experienced rider was chosen, who was wearing a backpack containing a laptop to record all the data. Additionally an open-faced helmet was used, as the special glasses would not fit inside a normal full-faced helmet. Wind and vibration cause the tracking to jump around, however a general sense of where this rider was looking is achieved.
  16. What Is Wrong With My Bp

    This was mentioned briefly earlier but have a look at this video if you have not already:
  17. New Article About The School

  18. Css...and Brakes

    Keith described trail braking braking very early on in A Twist of the Wrist Volume #1, back in 1982: “To get into a turn correctly, you must time the braking and turning so that the bike stays even, not going up or down, at the point you let off the brakes. You must let off the brakes at the exact moment your fork is compressed just enough for the speeds and cornering loads it will be undergoing through the turn. Apply the throttle so that the fork extension doesn’t change, or changes the least amount possible. This will allow you to go into the turn without any up and down motion. If your timing’s off, you may complain that the bike handles poorly, possibly thinking the shocks are gone.” P. 35 “Your target, or sub-product for any turn in which you brake and turn in succession, is timing the braking, steering and throttle so that fork and shock extension are kept as even as possible.” P. 35 “To go in perfectly, you would let off the brakes as you go into the banking just as the suspension is taking the load from the centrifugal force. This will give the smoothest entry. You back out of the brakes just as the turn takes over the job of compressing the suspension.” P. 36
  19. Vision Advice From Ken And Nick

    This Wikipedia quote should allow you to draw some conclusions of your own: Saccadic masking, also known as (visual) saccadic suppression, is the phenomenon in visual perception where the brain selectively blocks visual processing during eye movements in such a way that neither the motion of the eye (and subsequent motion blur of the image) nor the gap in visual perception is noticeable to the viewer. The phenomenon was first described by Erdmann and Dodge in 1898,[1] when it was noticed during unrelated experiments that an observer could never see the motion of their own eyes. This can easily be duplicated by looking into a mirror, and looking from one eye to another. The eyes can never be observed in motion, yet an external observer clearly sees the motion of the eyes.
  20. What May Have Caused This Crash?

    I'm very careful when answering in terms of physics because I'm not formally trained in physics and even if I was, a full explanation of the physics involved would be very long and quite technical. With that being said, we can take a big step back and say the majority of the single vehicle, loss-of-traction-in-a-corner crashes we have witnessed have been due to an increase of both throttle and lean angle simultaneously. This has been spoken about many times on this and other forums. One way of looking at it would be saying that leaning the bike over creates a turning arc, and the more you lean the bike over, the tighter the arc for a given speed and body position. Now if someone was in the process of leaning a bike we could say he was tightening his arc. Now throttle enters the scene: the throttle has a stabilizing effect on the bike and when applied smoothly evenly and constantly causes the bike hold a line. A lot of throttle would increase speed and widen the arc but not necessarily change lean angle much or at all. In other words good throttle control gets the bike to stay put on its line. Now if someone is applying throttle (saying to the bike "stay put on your line") and then leans the bike over further during that throttle application, essentially the bike is being asked to do two things in conflict with each other: 1) hold line and 2) tighten the line. The tire(s) give out when the forces are strong enough, meaning fast for the conditions. Whether it is the front or rear that gives out first would have so many variables connected to it that I could not begin to guess. "Weight on contact patch in a corner" does not all by itself guarantee traction or lack of traction. Downforce does but motorcycles only have gravity and a very negligible about of downforce. Cars at speed however do have downforce and it can be extreme in the case of an F1 car or similar winged-body vehicle. With an F1 car, grip increases with speed, but a motorcycle does not seem to gain or lose traction in relation to speed in a corner. It usually seems to hover around the max of 1g in a flat (not banked) turn.
  21. What May Have Caused This Crash?

    I was there. He added throttle and lean at the end. I pointed it out to Adam when we saw the video in the pits and he agreed.
  22. Is Body-Steering Ever Effective?

    I suppose what's really needed is a clear definition of body steering in the first place. Then an exact list constructed of each body movement and the response that the bike is supposed to make to each. For example: "Pressure on inside peg during mid-turn yields 'X' response from the bike." I have a feeling that no one is going to construct such a matrix because riders will go out, try it, and shoot holes in it. Therefore you will get statements like: "doing 'X' with the inside footpeg HELPS the bike do such and such" I myself have tried all sorts of pressures and weighting and swinging to see what it does to a motorcycle, and I still try them. Often one's conclusions are colored by a cognitive phenomonon called "confirmation bias" whereby when evaluating our own beliefs, we tend to seek out information that confirms our beliefs and ignore contrary information, even when we encounter it repeatedly. Newton's 3 laws of motion can be applied to many of these notions and often help clarify what's actually happening. I just saw On Any Sunday The Nex Chapter on pay per view. In it a waist-down paralized former motorcoss racer named Doug Henry rides a motocross bike with a cage built around him. Motocross "common knowledge" is that you steer MX bikes with the pegs. This is myth busted on the spot as Doug has no use of his lower body, though there he is turning and jumping his bike as good as a rider with full use of their limbs. All that being said it is very much agreed that body position affects the motorcycle in many ways, some obvious, others subtle