Jump to content

Dylan Code

Superbike School Riding Coach
  • Content Count

    168
  • Joined

  • Last visited

  • Days Won

    18

Everything posted by Dylan Code

  1. Your collection of data and research shows you are barking up the right trees. Here's some more data regarding tires: Per the Dunlop engineers tires grip in 4 ways: 1) Adhesion--the temporary chemical bond between the tire and surface. 2) Keying--the tire deforming and filling in all the nooks and crannies of the asphalt or squishing into the depressions. 3) Abrasion--the tire tearing from itself or wearing away. 4) Hysteresis--the energy storage and return by the rubber and partial conversion to heat. The first two can be looked at as static properties and the last two dynamic properties in my opinion. I'm still learning on all this stuff and when talking to the tire engineers, they don't have all the answers either. Heck, aviation engineers still can't all agree on exactly how a plane flies through the air!
  2. Thanks very much. We have more on the way!
  3. Yes, the amount of lean and overall speed from wind resistance would matter a lot. Turn-in rate would matter I suppose but not significantly. Wind resistance going straight requires a certain amount of power just to maintain a particular speed. A hypothetical example is here: 30mph=1hp 60mph=8hp 120mph=60hp 180mph=190hp
  4. The answer to the question is: from turn-in, off throttle, not trailing the brakes, the bike will slow at the rate of between 3mph to 8mph/sec. Lots of variables of course but that's the quick answer.
  5. I remember this thread from long ago about friction. I've been going into tire grip and the elements affecting it for some time and had this recently pointed out to me: The laws of friction were cited with regard to tires. But there just one problem: those laws only apply to RIGID objects. Because a tire is not rigid, the law would not hold true.
  6. Coaches find that between sessions if they wait for their student to come around the track that their tires cool down enough to not provide sufficient grip. So in some cases they can lose their temperature within three or four minutes.
  7. Try this video for warmer questions
  8. I've ridden many different tire sizes on different bikes and really can't tell much of a difference once I get a few laps on them. I've ridden a 1000 with a 180 rear and it was fine... if you A/B compared you'd feel the difference I'm sure. Slicks last longer than street tires, at least the Dunlops do. Heat cycles are what our coach tires experience all day long every day they are ridden. It may make a 3% difference but nothing anyone could feel easily. 1) Don't sweat the size issue. 200's are fine. The AMA 600 class used to run 200 rear slicks... 2) Get slicks if you want durability (and grip). 3) Use warmers with the slicks to ensure you don't get a cold tire crash. 4) Worry more about tread depth than heat cycles.
  9. Yes we sell those tires and also Chicken Hawk warmers.
  10. Slicks will last longer, maybe almost twice as long as the qualifier 4 rear.
  11. To directly answer your question: more handlebar turn. Same radius and speed, but less lean angle would be more turn of the handlebar into the turn.
  12. MotoGP riders are typically trying to dial up as much engine braking as possible. They can also dial it in or out for specific turns by GPS. If you are riding a track that is very "stop and go" with a lot of braking zones, I would dial it up. If it is a flowing track with transitions, I would use less engine braking so the bike does not pitch forward if you feather out of the throttle in a transition.
  13. Yes like mentioned above TTR125 or CRF150. I also recommend going to a school first that uses those bikes to try before you buy, like Rich Oliver's school or American Supercamp.
  14. The only reason there are no female racers in the MotoGP class is that too few enter at the bottom as youth racers. It probably takes between 3,000 and 5,000 youth racers to eventually end up with one who is capable of racing at the highest level. This includes having the family with the means and support and Olympic-level dedication to the child to make it past all the barriers to succeed.
  15. So the only way a motorcycle will even approach something like 2g's would be a very steeply banked turn.
  16. I don't think we will ever see a motorcycle pull 1.96 lateral G's on flat ground this lifetime. For comparison a Superkart on the skidpad did 1.39g in one test. In the same test a Williams F1 car with 0.5G downforce was able to do 2.0G on a track in a fast, banked corner aided by the wings for road holding. An Ariel Atom, known for its cornering, can only mange 1.12G, a Ferrari LaFerrari comes in a 1.16G. I think your calculations may be based off of some assumptions regarding the contact patch and it's location for the effective lean angle figure vs frame lean angle. I'm looking at a datalog of a moto2 bike at Aragon ridden by a world level rider, fastest lap, banked turn, and coming up with a max lateral acceleration of 1.42G as a momentary peak. The key point being that it's a banked turn.
  17. So if a MotoGP rider is leaned over in a corner on flat ground at 63 degrees of lean, what do you think the lateral acceleration is?
  18. Regarding the graphic of lean angle and G-force above: that would only hold true if the motorcycle had a theoretical "zero width tire". The apparent lean angle and the effective lean angle are different on a motorcycle due to the contact patch being off to the side versus straight down the center line of the motorcycle. For example a MotoGP bike at 62 degrees of lean is going to be more like 1.2G. That can also be skewed by the amount of banking. So the question would be how are we measuring the lean angle: against vertical or in relation to the road's camber? You can be perpendicular to the road in a steeply banked turn and register 20 degrees of lean from vertical...
  19. Recently Joe Roberts did a day of practice on one of our school bikes which he is familiar with. He had always rode it with a 200/55 rear but this time he used the new 200/60. As suspected the bike turned in very well due to the higher rear. The 200/60 is 10mm taller than the 200/55.
  20. Riding with one hand forces the rider to both push and pull on the bar... The push is in my opinion more accurate but the pull can help overcome the resistance for higher speed turns. Less necessary for a light responsive bike.
  21. I think this topic is simple enough to where someone can just go out and try it. In my experience I have seen every combination of rider with regard to preference on bar pressure but it does make sense that using both a push and a pull will give the most control.
  22. The schedule is up but the Laguna dates are not finalized yet. Should be up in 24-48 hours hopefully.
  23. Regarding ease of steering: you can push the inside bar (push right bar to go right...) but you can and should also pull the opposite bar. Some people have a hard time coordinating this if they have not done so before.
  24. Generally speaking you would want to apex it where it is the most off-camber.
×
×
  • Create New...