Having just bought a 2003 ZX6r I was wondering about the tire sizes, I have bought the bike with newish pilot power's but the sizes are all wrong, rear is 190X50X17 and front is 120X70X17, according to the manual these should be 180X55 and 120X65, I'm going to change the rear to a 180 but it's not so easy to get a 120X65, and I would prefer to keep the 120X70 as the bike will hopefully spend most of it's time on the track. Is it OK to use a 120X70 on the front? Any comments/suggestions welcome.