Speedometer WAY off

[fargofour]

Hi,

On my 98 GL150 SE the speedometer shows faster than I'm actually going, and it gets worse as the speed increases as measured by my GPS

Speedo - 40, actual - 35
Speedo - 60, actual - 50
Speedo - 95, actual - 75

The tires are Dunlop Elite 3, stock size. The Aspy has an analog speedo.

I know somebody once said Honda instruments are for entertainment purposes only, but this seems a bit extreme. Or do I just live with it and use my GPS for a speedo?

thanks,

Bud.

[WingAdmin]

The Honda speedometer will normally show a slight bit higher - but not that much. Mine reads maybe 2 mph higher at highway speeds than my GPS shows.

There's no mechanical failure in the speedo drive or cable that could cause the speedometer to read high, it must be something within the speedometer instrument itself.

[MikeB]

The stock front tire should be 130/70-18.

I have never seen a GL1500 speedometer off by that much if the stock tire size is used.

[fargofour]

Thanks for the replies. I'll check the tire again but I'm sure its the stock tire size.

May just have to live with it. And as long I know the equivalent speeds I should be OK.

Thanks again,

Bud.

[Swagonmaster]

You might check with a speedometer repair shop to see if they can't recalibrate that speedo for you, that's a lot of inaccuracy to have to deal with.

[bellboy40]

That seems odd that the speedometer on your 1500 is off that far. My 1500 speedometer is more accurate than on any other motorcycle I have ever owned, from the GL1000 on up. Mine is almost dead on with my GPS at any speed that I drive.

[MikeB]

That seems odd that the speedometer on your 1500 is off that far. My 1500 speedometer is more accurate than on any other motorcycle I have ever owned, from the GL1000 on up. Mine is almost dead on with my GPS at any speed that I drive.

Ditto.

[joeincalif]

I have owned several different Honda's. 7 Gold Wings and a number of other models, all have had speedo errors. Usually about 5 MPH at 55 MPH and up. On my 1800's I put a 70 series tire on the rear and that fixed the problem. I always put a GPS on all the bikes I have owned so I use that for the true speed and miles. my current bike is an 09 VTX 1300 "R" it is off by about 5 - 6 MPH at highway speeds. But I have my GPS on it also.

[fargofour]

Thanks again for your observations and suggestions. Does anyone happen to have the diameter or circumference of their front tire.

Bud.

[MikeB]

Thanks again for your observations and suggestions. Does anyone happen to have the diameter or circumference of their front tire.

Bud.

The diameter of the Avon Cobra Chrome AV91 130/70B-18 front tire in my GL1500 is approximately 24.6 inches.
The circumference is approximately 77.4 inches.

[fargofour]

Hi again

the front tire size is 130/70 x 18

circumference 77 3/4"

I don't know. I'll just use the GPS

[DarthJ]

That is pretty bad. My 1500 is more accurate than my car. Pretty much dead on when compared to GPS. Maybe check the cable ends. See if they are seated properly and that they turn freely. And the nylon gear. Couldn't hurt to give them a check occasionally for giggles.

[DenverWinger]

I don't have a GPS, but both my 1100 and 1500 speedometers agree with those "Your Speed is" radars found on city streets or highway construction zones....

My Jeep reads low compared to the radars, but it has 225 series tires where spec is 205's