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It doesn't have to be linear. \\; The sensor feeds the computer which in turn drives the speedometer display. \\; The computer can interpret the pulses from the sensor any way it pleases.
My speedo says I am going 3 mph faster than the zumo 550 displays. I guess I haven't paid much attention to it at lower than highway speeds. At 70 on the speedo, zumo says 67. Stays about 3 mph off until I get up to about 100 mph.
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After 100 mph, the speedo starts climbing faster than the zumo. When the speedo is buried, the zumo says 114 mph.
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Dennis
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My speedo sucks ... 2008 Ultra Classic
When my speedo shows 75, I am actually doing 69-70 (6.7% deviation). Dealership says that is acceptable (to them, NOT to me) ... idiots.
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I'm looking at the SpeedoHealer and the SIM-1 product from Dakota Digital. If I can ever figure out how to install one of these, I'll probably do it.
The speedo difference also runs your odometer up artificially. \\; The bike will show more miles than it actually has. It also makes your gas mileage look pretty good. \\; :-(
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I've got just the opposite. \\; My odometer records less mileage than actual. \\; Checked it with Gps today. \\; Across 21 miles, it was off 3/10. \\; Going to try it on a longer ride to see if the ratio holds up. \\; So, I guess I have been underestimating my mileage, and I was actually rather happy with what I was getting. \\;
We have those self contained towable radar machines everywhere here in CT. \\; I can't help but blow threw them at twice the speed limit and set off the lights anyways they usually read about 3mph slower at 60.
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