Re: Speedometer Accuracy

[andrew johnson <sundiaL@xxxxxxx>]

At 8:32 AM -0700 6/1/05, Gregory Appling wrote:
>The bike in question: 2002 R1150r
>
>Does anyone know how accurate the speedometers for the R1150r's are? 
>I'm currently trying to figure out if my speedometer is way off or 
>if my GPS units is just so cheap that it's not even close.
>
>Yesterday while running down the highway my speedometer read 92mph, 
>my GPS read 81.7mph and my girlfriends SUV (following closely) was 
>somewhere around 85mph.
>
>Just wondering if this is normal or time to take it in to be checked 
>(still under warranty).
>
>Thanks for any help.
>
>gregory
>
>2002 R1150r
>1975 R90/6
>ABC# 8111
>BMWMOA # 117910
>San Francisco, CA

It's probably off, reading from 5% - 8% high (fast). BMW does this so 
you can't claim you were traveling faster than your speedo indicated 
(they don't want to be held liable for your speeding tickets).

A common fix for the GS 1100/1150 is to take a speedo hub from a 
spoked R1100R wheel and get accuracy within 1%. The R1100R hub for 
spoked wheels has a different ratio that almost perfectly solves the 
problem for the GS.

http://www.advrider.com/forums/showthread.php?t=701

Other solutions for cable-driven speedometers use ratio-changing gear 
boxes to correct for the variation.

- -- 
- - andrew, Berkeley, '00 R1150GS
- - "Moto per Mangiare, Mangiare per Moto"

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