Really can't really say for sure if changing the rear will alter the speedo reading,just what i've heard from friends that have done the mod, but if the sensor reads off of the gearbox then it won't be an issue anyway.Originally Posted by Gav
As for the small front sprocket increasing wear,1 tooth down will have a negligible effect as I have 1 down ,1 up and still get 10k+ out of a chain and you have first hand experience on how i can ride my bike......don't you Gav! (Chain life is all about keeping it well lubed)