summed up in a few words. reliable as gravity, and then some. CBR600's are tough bikes and built well. if you change the oil when you're supposed to, keep it clean and take good care of it, you'll likely see 200k or better from the bike before you're considering rebuilding. the cam chain tensioner might start to rattle, but thats the ONLY flaw I've heard of on a CBR. its easily fixed with a manual one too.