Quote Originally Posted by viper84737 View Post
I did not mean gearing. I meant SpeedoHealer and SpeedoDRD devices. My understanding is that the signal comes from a single source, a wheel speed indicator, which is then translated into a speedometer reading via simple math. Since that signal doesn't seem to be interrupted in any of these devices, then split off and calculated separately by the ECU, I fail to see how one can change just the speedometer reading without affecting the odometer value itself.

Are you 100% SURE they calibrate BOTH speedometer AND odometer to correct values? If so, can you provide evidence, for I have testimony to the contrary.
Not sure exactly what you mean by this?
On my bike if you change your gearing your odometer and speedometer will be effected.
From the speedohealer website in the FAQ section (#5) it says since there is only 1 speed signal it will calibrate them both: http://www.healtech-electronics.com/