Another concur here..... As mentioned above, the resounding trend with among modern Jap bike owners is 6-8% optimism; though interestingly enough....my odometers have always been correct, as verified not only by GPS, but also roadside mile markers. Stated another way, an incorrect speedo does not necessarily mean one's bike is collecting (getting cheated out of) miles faster than actuality.
I read an article a while back that the industry errs optimistic, providing enough margin to compensate for variances in wheel / tire construction, such that the indicated speed is never slower than actual. It reported that German-made vehicles are the worst offenders, sometimes reaching 10-12%. Just what I read....not personally verified, don't shoot!
