[QUOTE="Chris H"] I've had every different version of the cbr600f and none of them revved at less than 4k at 30mph in 2nd. Whatever was wrong before, it's now right.[/QUOTE] 30mph / 4500rpm = 0.0066666666666666666666666666666667mph per revolution of the engine x 8000rpm = 53.3mph; a speedo is likely to over-read more the faster you are going, by design, not under-read... so I think not. [QUOTE] Oh and what everyone else is saying about clutch slip and synthetic oil is not true.[/QUOTE] *Some* bikes are affected by it, others aren't. Not everyone uses OEM parts for example, when replacing a clutch, so who is to say this side of properly conducted tests, whether one particular brand of clutch plate is going to be affected in this way, more than another... Given the above calculation, I'd say he's definitely got clutch issues, for some reason. [QUOTE] I've always used synthetic and never had clutch slip problems despite severe provocation.[/QUOTE] [QUOTE] HTH[/QUOTE] Not really, because I've had problems with using synth in the past, in *some* bikes, and not others, with regards to the clutch... which IME means it applies to *some* bikes, and not others.