Fabrice thanks for the reply the reason I asked about the wheel is because the 450 I wrecked had an excel rim on it 1.67" which is best protected by the tire for hard off road. As for the Brakes and telelever I agree there is no way the std yz brakes will stop the GS but there are 320mm Discs available and a descent calliper is going to have to be fabricted up to suit. The telelever definetiley has its limits off road on rough surfaces you can go up to a certain speed but is to unstable above that. I had a we crash a couple of years ago and ended with one of these
and a pile of spare parts as I repaired it myself. I am currently working on my project starting with a frame.