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Hi everyone,
Before I go any further, I just want to say that this is just a theory and I'm not saying this is absolute truth with a Genius hat or anything. Maybe I'm completely wrong here.
Yesterday I rode at a racetrack that has a lot of bumpy 2nd gear accelerations while picking the bike up (for those who know it, Carole in France), and I encountered the same kind of wobbles than in GP bikes: strong ones, and that remain for about 50 meters with a large amplitude.
I thought about it while at the racetrack and determined the reason to be this one:
- when picking the bike up I am countersteering by pulling on my inside hand (some people push on the outside one, but it's harder to do when you're hanging off the bike),
- at the same time my bike was starting a wheelie on the bumps (front end got up very slightly, maybe 10cm),
- the result is that my bars were turning slightly during the wheelie because of the pull on the bars,
- my front wheel lands on the ground while turned
- wobbles after that, and by keeping the throttle wide open it would go away.
Now this is nothing new really, I remember seeing 500 GP riders in assen in 2000 and 2001 who always had the same problem at the beginning of the straight (coming out of the chicane) but I'm thinking this is the exact same kind of behavior than in GP bikes.
This video illustrates what I'm talking about (the wobbles are smaller here, because, well, he's just much better than me - also, notice the fine rear brake use, but that's not the subject today):
https://www.youtube.com/watch?v=lxyNCr-98ZU
I was able to correct the problem by losening my arms when the wheelie starts.
So I'm thinking that maybe in GP bikes what happens is that the rider input to pick the bike up involves counter steering and that this input continues even when the wheel is off the ground maybe? And then the front wheel is missaligned and produces wobbles. Maybe there should be an option to lessen the input when the wheel is up? I don't know.
Also, one thing I still do not understand is why do we have to cut the throttle to kill it instead of keeping it wide open like in real life (which works).
Anyway maybe my theory is misleading but I just figured I should talk about it in case Piboso reads it.
Before I go any further, I just want to say that this is just a theory and I'm not saying this is absolute truth with a Genius hat or anything. Maybe I'm completely wrong here.
Yesterday I rode at a racetrack that has a lot of bumpy 2nd gear accelerations while picking the bike up (for those who know it, Carole in France), and I encountered the same kind of wobbles than in GP bikes: strong ones, and that remain for about 50 meters with a large amplitude.
I thought about it while at the racetrack and determined the reason to be this one:
- when picking the bike up I am countersteering by pulling on my inside hand (some people push on the outside one, but it's harder to do when you're hanging off the bike),
- at the same time my bike was starting a wheelie on the bumps (front end got up very slightly, maybe 10cm),
- the result is that my bars were turning slightly during the wheelie because of the pull on the bars,
- my front wheel lands on the ground while turned
- wobbles after that, and by keeping the throttle wide open it would go away.
Now this is nothing new really, I remember seeing 500 GP riders in assen in 2000 and 2001 who always had the same problem at the beginning of the straight (coming out of the chicane) but I'm thinking this is the exact same kind of behavior than in GP bikes.
This video illustrates what I'm talking about (the wobbles are smaller here, because, well, he's just much better than me - also, notice the fine rear brake use, but that's not the subject today):
https://www.youtube.com/watch?v=lxyNCr-98ZU
I was able to correct the problem by losening my arms when the wheelie starts.
So I'm thinking that maybe in GP bikes what happens is that the rider input to pick the bike up involves counter steering and that this input continues even when the wheel is off the ground maybe? And then the front wheel is missaligned and produces wobbles. Maybe there should be an option to lessen the input when the wheel is up? I don't know.
Also, one thing I still do not understand is why do we have to cut the throttle to kill it instead of keeping it wide open like in real life (which works).
Anyway maybe my theory is misleading but I just figured I should talk about it in case Piboso reads it.