The odometer on my daughter's bike is a simple one. But I can't get the setting right. I looked online and got the number, but when we are biking side by side it shows her as being about twice as fast as me. (I know that her computer is the wrong one, not mine, because I know we are not traveling 20 mph on average!) I took a tape measure and marked the wheel with chalk and measured it, and got a number that was pretty close to the one I'd found online, and I entered that into the computer. Her bike still thinks we are cruising at 20 mph!

She likes it that way. I'd prefer to have an accurate mileage reading on that bike for maintenance logs. Any ideas what's wrong? It's a Sigma Sport, walmart brand bike computer. It might have cost all of $12. I've been assuming that it's me entering something wrong, but it did just occur to me that maybe the computer is actually programmed wrong, or some glitch occurred. It used to work, on her old bike.