I have a ZZR250 with the original sized chainring on the back.....all pretty sweet, except trying to "cruise" at 100-110-Km/h it is revving at about 8k rpm. Yes, i know this is the usual 250 setback..........but I had an idea. Why don't i just get a smaller rear sprocket to give it a bit more "top end". I know first gear can handle being taller, i hardly even need first gear normally. Has anyone done this? What are your thoughts? Thanks.