Calibrating speedometer

[Flashdog]

Since new my 02' R1150R's speedometer has read high. At 65 mph it reads 70 mph. It does get more worse as speed increases. I've lived with it for 26K miles and it may have even saved me from a few citations. I'm just not one of those people who set their alarm clock ten minutes early to fool themselves. Because the speedometer is off then my odometer is off so I have accrued more miles. So I guess my bike has more like 25K miles.

It is cable driven off of the front wheel. I have kept with the correct tire size. Is there any internal adjustment in the speedometer that could be adjusted?

[boxermania]

Nope....actually you kind of hit it on the head....typically bike speedos are ~ 5 mph slow for the reasons you described. Some if it can be corrected by altering the OD of the tire by increasing or decreasing the tire pressure, but the gain/loss will be small.

Don't worry about the speedo and enjoy the ride.....welcome aboard.

[sweatmark]

I don't think it's worth your time or money to attempt any calibration of the speedometer, but you can get expert opinion from these folks:

http://www.paspeedo.com/bmw.htm

With the availability of inexpensive GPS units, the issue of true vehicle speed (and the correct atomic clock time) is addressed once and for all. You can get a moto-capable unit in many flavors from Garmin, TomTom, etc.

We have used the Garmin Rino GPS/radio units with excellent success on our bikes:
http://www.garmin.com/products/rino
I also bought a cheap reconditioned Garmin StreetPilot with integrated XM radio for $350 last year, but you can spend a good deal more depending on the functionality you want.

Another good option for getting true bike speed is use of a cycle computer. There should be some info posted around the board here about using a good Sigma cyclometer unit as auxilliary speedometer:
http://www.aerostich.com/catalog/US/Sig ... 19100.html
Do a search here, though the info might have been posted on the original Roadster board.

Let us know what you choose to do!

[Flashdog]

I've got a TomTom on a Ram mount and a Garmin Etrex Legend. I was just hoping to calibrate the speedo.

[towerworker]

They all do that.

[sweatmark]

Ask Palo Alto Speedo about the possibility for calibration. Like Tower says, they all show 5-10% optimistic speed, and we mentally calibrate accordingly. But seems you've already got the gizmos to measure true speed!

Mark
Bellevue native, relocated, Kidd Valley Burger advocate

[Flashdog]

Hey Mark. We moved up here from Florida because my wife found a job in Bellevue. We were trying for Oregon. No regrets, we love Washington! There's a Kidd Valley in downtown Kirkland so I'll give it a shot this weekend. Thanks!

[Arjen]

... Because the speedometer is off then my odometer is off so I have accrued more miles. So I guess my bike has more like 25K miles. ...

Nope.

My speedo is about 5-10% optimistic, but my odo is 4% pessimistic.
Both compared to a Garmin GPS.