For those of you running the Big Gun Exhaust on your XR600R's-be aware that on hard landings your front tire may come into contact with your pipe! I took my bike out to an MX track recently and was really enjoying the jumps. The landings? Not so much. Anyway, it appears that on hard landings the front forks were compressing enough that they actually allowed the front tire to contact the header. For some reason, it only made contact with the LEFT side tube on the second bend. The tube comes out of the head and makes a downward bend-1st bend-then goes for a short bit and then makes a bend to the right-2nd bend-and this is where the tire has been making contact. I was looking at the bike trying to figure out what could have caused the rub mark on the header. After studying it for a while it occurred to me that it must have been the front tire. New front tire + Very hard landings + After Market Exhaust=UCI (Unintentional Component Introduction). Now I have a set of custom pipes.. That one spot where the coating is missing will soon rust-making them custom!