I posted this here because I wanted a racers perspective.
In the later half of this video (sorry if it is a repost) You have to watch a little way into the video before you can see the modern bikes.
http://media.putfile.com/TT2005retro
The bikes have what I consider a tremendous slow oscillating high speed wobble. I have never felt this on my 04 r1. I have felt going about a 130 while slightly wheelied in a turn, when the wheel met back up with the pavement a very fast oscillation wobble. My handlebars almost shuttered and danced back and forth maybe a half an inch in each direction about 5 times and then it stopped. It was not unnerving or scary. It twitched about 5 times in the amount of time it took one of the bikes in the video to wobble once.
So my question is, why are these bikes wobbling like this? Is it just they are old technology or are the bikes not set up correctly or are they set up this way on purpose so they turn much better sacrificing straight line ability? Or is there some other reason. I want to know because, I don't want my bike to do what theirs is doing when I am going fast. It even appears they wobble while on the rear wheel while in a wheelie!
Also I am building a super moto kx500 and because of the different sizes of the wheels 17-17 compared to 21-18 and the fact it has no steering damper like the R1 does, I am a little worried about the change and will it change geometry due to the front wheel being smaller and placing the rear of the bike higher. Normally in motocross if you raise your back end steering gets sharper and may even knife but you can also pickup head shake. I want understand why this is happening so I can prevent it on both bikes. I sure anyone that races knows of this effect, why it happens and how to prevent it. If you have some time type the answer or a web pointer would be nice too.