Total Motorcycle Community Forums

BMK wrote:I'm not buying it.
It would seem to me that a manufacturer that would knowingly and intentionally set the speedometer inaccurately (fast or slow) would open themselves up tp all kinds of legal problems and lawsuits. It doesn't make any sense for them to do it....theres nothing for them to gain and quite a bit to lose by such a practice.

bingo!!!

check out the class action suit against honda

Like I said, just a theory. Then you can throw in different tires sizes, a 180/55/17 can vary by up to 1 inch in diameter depending on manufacturer, gearing inconsistencies, temperature fluctuations, and inefficiency of data retrieval/transfer.

Gadjet wrote:My bike speedo is off by 10%, as calibrated with my GPS. I don't consider this to be a problem though, as I'm used to it and I now use my GPS for speed readouts.

i've always wondered how accurate the gps is at calculating speed?? can it be used reliably to determine your road speed??

anarchy wrote:

Gadjet wrote:My bike speedo is off by 10%, as calibrated with my GPS. I don't consider this to be a problem though, as I'm used to it and I now use my GPS for speed readouts.

i've always wondered how accurate the gps is at calculating speed?? can it be used reliably to determine your road speed??

GPS is very good at calculating speed. It is more than reliable enough to determine your speed and calibrate a speedometer.

I can't attest to the validity of this statement.

From what I've read on other forums for bike's that address a slow speedometer, stromtrooper.com most recently. Manufacturers intentionally set the speedo to be anywhere from 5-9% faster than your actual b/c there are regulations in many countries that state if a speedometer shows a SLOWER speed than you are moving as set by the factory then there are heavy fines and penalties as well as a requirement to fix all effected bikes. Thus, by setting the speedometer to 5-9% slower, no matter what sized tire you add to the bike (w/o serious modification I'm sure) this will never be an issue.

anarchy wrote:check out the class action suit against honda

From my understanding of these law suits certain honda cars are overstating mileage which would hurt it's overall value. If anything a motorcycle speedometer showing a slower speed is understating mileage. I wouldn't complain about that.

It seems to be very commonplace. I don't know why (and don't even care why) the manufacturer would mis-adjust the speedo. I just know, from both practical observation and from comparing my speed to our village's roadside radar readout, that my bike is definitely 10% off (reading higher). So I just keep it in mind when I'm traveling.

Cheers,
Loonette

Loonette wrote:I I just know, from both practical observation and from comparing my speed to our village's roadside radar readout, that my bike is definitely 10% off (reading higher). So I just keep it in mind when I'm traveling.

+1. I know at 75 indicated I'm only doing about 68 actual.

wow. i love this site. i learn so much from you all.

I have suspected my speedo was reading a bit faster than i am really going. I don't know how much, but maybe 7-10%.

If you really care to fix the issue, get one of those $20 bicycle speedos/computers. You feed it your wheel diameter and it tracks rotations with with a little magnet. Very accurate and a cheap trick.

A good search on this will most likely bring something up. I read about it a few years ago.

My speedo is off about 8-10%, but I dont really care enough to do anything about it.