Speedo issue

[Snappy1]

My speedometer has registered 10% slow since I acquired the bike 5 years ago. Is there a way to adjust the speedometer for accuracy? Possibly a different gear at the front hub or an adjustment at the speedometer head itself? I am to the point where I NEED to replace my front and rear tires. A 10% reduction in the front tire circumference would accomplish the same thing, but the existing tire is the correct size and downsizing the tire to correct this issue wouldn't be causing another. Suggestions?

[93gc40]

5% is normal. You can try a different tire. Most bike riders just get used to the Speedo error, or get rid of the speedo.

[miniphantom]

There are also devices you can buy that will do the correction. 12oClockLabs sells one, but they are not the only place.

[jpr1968]

Does your speedo actually read slow or does it read about 5-10% fast. Everyones speedos usually read high which is no biggy. If were readin low then that could be a different issue.

[adlowe]

Originally Posted by Snappy1

My speedometer has registered 10% slow since I acquired the bike 5 years ago. Is there a way to adjust the speedometer for accuracy? Possibly a different gear at the front hub or an adjustment at the speedometer head itself?

Yes. Those electronic gadgets won't work for you (or me) so don't waste your time on them. Your system is completely mechanical.

Going through all the pieces/parts required to change the reading has not been done AFIK. (Making such a big change in the front tire diameter does not seem like a good solution to me.) Easier than all of that, though, is getting a new face printed for your speedometer -- one with different "spacing" on the numbers. I've got links for a site or two for ordering custom speedometer faces; let me know if you're interested.

As for jpr1968's question: He's right. My speedometer, for example, reports a higher speed than I'm actually traveling. That is the bias most vehicle manufacturers build into their designs. I'd be surprised to learn that there's one out there with 10% error in the opposite direction.

[halifax]

Originally Posted by adlowe

My speedometer, for example, reports a higher speed than I'm actually traveling. That is the bias most vehicle manufacturers build into their designs.

Yup.

This is my first V-Twin powered bike and vtwin cruisers are at their best when ridden slowly, I think.

So...I've been trying to ride under the speed limit, which means riding the indicated speed limit on my gage.

[adlowe]

Originally Posted by halifax

Yup.

This is my first V-Twin powered bike and vtwin cruisers are at their best when ridden slowly, I think.

So...I've been trying to ride under the speed limit, which means riding the indicated speed limit on my gage.

Just about the only time I know how fast I'm going is when I spot a LEO. Maybe sometimes when I'm riding without any other traffic at all. Or in a school zone on a school day. Other than that, it's just a number I ignore.

[93gc40]

Originally Posted by halifax

Yup.

This is my first V-Twin powered bike and vtwin cruisers are at their best when ridden slowly, I think.

So...I've been trying to ride under the speed limit, which means riding the indicated speed limit on my gage.

NOT all cruiser are meant to be ridden slow. A Harley yes, your Shadow not so much. Your Shadow make Torqur in the midrange and HP at the upper end, where a Harley for example makes its power on the bottom end to midrange.

You will have to determine, via pacing or radar or GPS, the actual error of your speedo. While 5-10% is typical, it could read either fast or slow. Cars speedos tend to be more acurate but even they are not perfect. GPS or Radar is the most acurate, but even GPS can vary depending on which satelites its working off of, and your angle to the satelites.

[adlowe]

Originally Posted by 93gc40

You will have to determine, via pacing or radar or GPS, the actual error of your speedo. While 5-10% is typical, it could read either fast or slow. Cars speedos tend to be more acurate but even they are not perfect. GPS or Radar is the most acurate, but even GPS can vary depending on which satelites its working off of, and your angle to the satelites.

It's been a while since I checked the regulations but I believe that 10% error is permitted and it can be high or low. In practice, the OEMs do there best to make the range 0% low and up to 10% high, i.e. reporting a higher speed than the vehicle is actually traveling but almost never a lower one.

Car and truck speedometers have been consistently more accurate than motorcycle speedometers; I view that as a function of volume. (Car and light truck sales in the U. S. run between 12 million and 17 million per year -- a LOT higher than motorcycle sales.) Modern (those made in the last 3-4 years) GPS receivers are far more accurate than just about anything short of a race-timing systems and more accurate than most of us can read off the dial-gauge speedometers.