Tuning the speedo

[pmdave]

A couple of months ago I noted that my speedometer didn't agree with my GPS. The salesman who sold me the bike went to bat for me at Southsound BMW, and they changed the speedometer under warrantee. Better, but even the new speedo read higher than actual by roughly 5-7 mph. I don't think I'm anal retentive, but I wanted to see if I could tune it a little closer.

So, I obtained a 2.875 speedo drive and installed it. With a half-worn front tire, the speedo now reads just 2 mph higher than actual--which is close enough for me.

I assume that if I install a new front tire--or change to a more aggressive dual sport tire--the speedo might actually read a little slower than actual. The factory can't chance that, but I'd rather have it closer to actual on average.

Swapping the speedo drive was easy. Just loosen the cap screws, pull the axle, drop the front wheel, clean up the cavity, insert the other drive, and reassemble. Maybe 30 minutes. The brakes don't have to be removed.

2.875 speedo drive is part no. 621 2230 6532 $44.75

pmdave :thumb

[MCMXCIVRS]

Was your odometer out equal to the speedometer? My speedometer is dead on to my GPS, but my odometer reads 2% high. If I fixed the odometer then the speedometer would be out :dunno Unless there is some way to recalibrate just the oddometer internally without affecting the speedometer, I'll just continue to live with it. This way I get bonus bragging miles :clap

[dano]

I was told at one time, that if you're not happy with the accuracy of a speedo, you can go to a "speedo shop", and they can install an in-line reduced / increased drive unit.

They will calibrate what drive you need and the ratio. I was also told that it's not cheap by any means, but it can be done, and be 100% accurate.

[BradfordBenn]

But if I know how fast I am going, there goes reasonable doubt... Not that I encourage or endorse or am involved in breaking the posted speed limit.