Re: Speedometer

Roberto /
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That's an interesting suggestion that would be true - if your tire is low you would read a higher speed than actual.

My experience is that there is a fundamental problem with the speedometer design. It's basically a magnet that spins inside a little "cap", that is attached to the speedometer needle. As the magnet spins it creates edy currents in the cap, that pull it in the direction of rotation. The problem with this is that the pull force doesn't increase the same as the spring force that pulls the needle to zero (there are losses in the edy currents at high rpm and the spring force is not the same the more you unwind it). I've noticed that up to about 25-30mph it's correct, but when you start doing 55-65mph my speedo reads 65-80 mph. I'm assuming that my moped behaves the same way (although I haven't tested it) because they use the same speedometers, just different drive gears and face plates.

This single post is part of a larger thread. Start from the top or view this post in context.
Subject Written By Posted
  SpeedometerTopic by: Wayne Broderick Wayne Broderick 06/26/01 10:27PM
  Re: SpeedometerRe: don-ohio don-ohio 06/26/01 10:49PM
  Re: SpeedometerRe: Rick Rick 06/27/01 12:59AM
  Re: SpeedometerRe: Roberto Roberto 06/27/01 10:50AM
  LISTEN TO ME!!!Re: mike mike 06/27/01 10:15PM
  Re: LISTEN TO ME!!!Re: don-ohio don-ohio 06/27/01 11:04PM
  Digital SpeedosRe: Chris Robertson Chris Robertson 06/28/01 11:04AM
  Re: Digital SpeedosRe: Wisky Wisky 06/29/01 10:00PM
  Re: Digital SpeedosRe: Chris Robertson Chris Robertson 06/30/01 05:24PM

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