You can spend lots of money for very little gain, I have spoken to my mate who races an R1 in the Mallory series and his mechanic who owns a yamaha dealership, both say do nothing but the sprocket, because there are no low down gains to be had.So my fix is ride it like a two stroke and dont let the revs drop, it doesnt seem to effect fual consumption that much.Fit loads of stuff if you want braggin rights, pub talk or like to alter the looks, but not to gain low down grunt, ride it, enjoy it.