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Showing content with the highest reputation since 03/13/2019 in all areas

  1. 1 point
    Hey guys. I wanted to share some videos I made of me analyzing data of of my lap vs WSBK rider who is also riding my bike around Chuckwalla CW direction. So far I have made 3 videos that are very basic, but a good place to start because they are simple and hopefully easy to understand. My qualifications: I used to race cars, and we were very heavy into data analysis. I also spent many hours with crew-chief of Tech3 and Data Engineer for Gresini which we covered in detail all aspects of data acquisition for motorcycles. Software and data acquisition system: "2D Data Recording" (used on all moto3, moto2 and many MotoGP machines) The videos should be watched in order because they sort of "build" on top of each-other. Video #1 (time spent at lean) https://youtu.be/aJ_E-sUxJc8 Video #2 (roll speeds) https://youtu.be/aUDGNg2WDDM Video #3 (how it is possible that my roll speed is lower and my lean angle is higher) https://youtu.be/02q4I4xnyLc Future videos will all compare WSBK rider lap with my own (order not yet decided): - Roll Rates. How fast do we add or decrease lean angle. I will also cover counter steering, and how it works - Changing Radius during cornering. Entry, neutral, exit type corners and V-type - Motorcycle dynamics (will be many separate videos). Lean angles converted to G's. How to calculate lean angle from radius and speed and the other way around. What are G forces. Braking G's, acceleration G's, combined G's (traction circle). Why a bike does not fall and a self correcting system (rake, trail, offset). Anti-squat. Tire coefficient of friction. Camber thrust. - Focus on entry phase of corners - Focus on mid corner phase - Focus on exit phase - Suspension setup by suspension speed histogram to adjust rebound, compression scientifically. - How to find more time at a given track without a reference lap. - Oversteer & understeer - Sprocket sizes and gear simulations on the software. - Throttle acceptance - Xavi Vierge data analysis from Valencia Qualifying 2016. This will be fun. He brakes at 0.9 G's at 50 degrees lean! Woohoo! - Contact patch. Does a bigger contact patch actually provides more grip? (this one will really piss some people off) - Ideal Tire working temperatures, how we can find them, and how we achieve them. - Yaw
  2. 1 point
    Interesting! The third video may also show why quick steering is so beneficial since it allows the choice of a more efficient line. It also explained how one rider could corner at a given speed around a corner, fully decked out, while another can go faster and barely graze a peg feeler; different lines around the corner that require different amounts of lean for the same speed. Thanks for clarifying that. BTW, you may want to check your tags as I get a lot of animal video suggestions when watching yours, but nothing relevant.
  3. 1 point
    Hey Faffi. The article from cycleworld pretty much explained what is happening and this phenomenon of why moto3 corner faster than motogp so I suggest you read it very carefully. The MotoGP video is leaving out some important details in order to glorify and promote moto3 in with this concept of "hey, moto3 still has its strong points, they corner faster". Sort of like - rooting for the underdog. The reality is that moto3 bikes do not do anything better than motogp bikes besides maybe the flick rates (from side to side). They certainly are NOT capable of cornering at a higher speed than motogp bikes and the article from cycleworld alluded to that fact. I'll try to explain again. Imagine a motorcycle doing circles in a parking lot. Constant radius circles non stop at a constant speed. The higher the lean angle, the faster these circles can be negotiated regardless of the weight of the bike. At a certain lean angle, a given motorcycle tires would start to slide. This is dependent on the coefficient of friction of the tires. If the tire coefficient of friction is 1, anything past 45 degrees would result in a slide, and if not corrected, a fall. If the tire coefficient of friction is 2, anything past 63.4 degrees would result in a slide, and if not corrected, a fall. We know that motogp tires have a higher coefficient of friction compared to the japanese made KR133 dunlops used by moto3. So moto3 bikes can not lean as far as motogp bikes. The article explained this by how moto3 riders do not drag their elbows, but motogp do this frequently, and even tuck in their elbows a bit to allow even MORE lean angle. I will try to get moto3 data for Valencia and compare it to moto2 data to compare max lean angles and see which achieve higher. I know moto2 usually do around 56-58 degrees. Motogp can get to 60-63. So why do moto3 bikes have a FASTER mid corner speed than Moto2 or MotoGP? The article also explained this. It's because moto3 bikes do not have high acceleration potential, so their biggest "tool" for speed is momentum and mid corner. Any 1mph they overslow in mid-corner, is a 1mph they will very much struggle to get back. So moto3 riders choose to put emphasis on the corrector strengths of their machines by choosing lines that have the absolute highest radius. MotoGP riders will purposefully create a tighter radius in the entry part of the corner, in order to greatly increase the radius on the exit portion, so they may unleash their 260hp. If a MotoGP bike used the exact same line as a moto3 bike, it would not be competitive compared to other MotoGP bikes as it would not be able to get on the gas early and hard. But its mid corner speed would be greater than that of the moto3 bikes because it is able to achieve higher lean angles due to its greater tire coefficient of friction. Please remember, for constant radius, the only thing that can increase speed is lean. Maximum lean is maximum lateral G's the tire is capable of. Weight of the machine, has nothing to do with it. So what to do? Get stickier tires and you can lean more and you can have more speed at the max lean portion of every corner. Hope this helped clarify.
  4. 1 point
    Trying to find whether the smaller bikes corner faster - or not - I found this: https://www.cycleworld.com/sport-rider/motogp-extreme-lean and
  5. 1 point
    He talks about racing lines, braking, battling vs riding alone and more https://www.crash.net/motogp/news/915429/1/vinales-alone-i-can-make-lap-time-then
  6. 1 point
    I hope the current D208 are something else than the Sportmax D208s I had on the CB400 back in 2013! Most slippery rubber I have ever ridden on, by a big margin. They were original equipment on the DRZ400 motard allso, and may have worked on 100F sunny days, be we do not get those here. Ever. Sport touring tires work quite well when cold, and also warm up much quicker in my experience, compared to sport rubber. Even touring type bias ply will out-perform sport rubber under some conditions. I'll bet that on a day with 20-30F, something like a set of Metzeler ME77s will offer a LOT more grip than any modern sport radial made. At least with street tire pressure. In short, there is nothing wrong with sport rubber, but they are made for a purpose. Riding on public roads at respectable (as in legal) speeds in chilly temps are not such a purpose IMHO. In fact, even on a hot day, at a sensible pace for public roads, I doubt any pure sport tire will offer the grip of a sport touring model.
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