Odometer/Speedometer Error

When I bought the ST, I knew there were some inherent errors in the speedometer. Much of the discussion on the Internet says that it's in the range of 6%-8% generous. I know that when my speedometer shows 80 mph, I'm actually only doing about 75+/- mph. That works out to be about 6%-7% for me.

Although all the discussions I've read have been about the speedometer, I've read very little about the odometer. That's not to say that the discussions aren't there, I just haven't seen or read them. Today I went on a ride with a few friends and decided to bring my GPS along. Bringing the GPS along is actually a regular occurrence, but today I wanted to compare GPS distance to the odometer distance; I hadn't done that before.

At the end of the ride, my odometer showed a trip of 151.7 miles. The GPSr showed 145.1. An increase of about 4.5%. I asked my riding buddy how far his trip meter showed: 144.8.

I've heard that motorcycle manufacturers make their speedometer with an error on the plus side. Apparently it's for safety purposes. If we think we're going faster than we are, we'll slow down sooner and not get hurt. I'm not sure what the logic is here: motorcycle manufacturers have created some very powerful, highly refined vehicles, why can't they get their speedometers and odometers to measure correctly. And, if they don't trust us to know how fast we're really going, should we really have, or should they manufacture. a bike that can go that fast anyway?

1 comment:

irondad said...

I also read somewhere that the variance is to account for the different tire sizes a rider may use on the bike. There seems to be a little marketing, too. Riders feel better thinking they're going faster than they are.

I totally agree. Why not just make the instruments accurate?