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Speedometer vs GPS

4K views 12 replies 11 participants last post by  Wavefront 
#1 ·
Not a huge deal for me but I have been noticing that while on the highways and doing the exact posted speedlimits e.g 90kmph or 100kmph that too many cars are passing me. So with my wife in the truck using the GPS speed we checked it. Here are the results
GPS=90 CBR500R=105
GPS=100 CBR500R= 114

This is quite annoying as I didn't realize it was that far out. Of course the easiest is to check all speeds from 50kmph to 110kmph and then always do a mental calculation and increase the speed.

What about re-calibrating the speedometer? Is there a way to do this at the repair shops?

Mine is a 2013 CBR500RA it has 26,000kms and it seems to have been this way since I owned it at 6000kms.
 
#2 ·
yours seems to be a bit more off ...
in my case was it approximately like this (gps / speedo):
50 / 52 km/h
90 / 96 km/h
130 / 137 km/h
i know there are some speedo healers (just google cbr500r or cb500 speedo healer, you will probably get the most hits like that) on the market and you can also bring it closer by changing the gearing for more speed (bigger sprocket in the front or smaller in the back), at least that's something users that changed the gearing are reporting (that it is closer to the gps speed), also tire wear will influence your speedo readings as you are changing the circumference of the rolling part and the speed is measured at the crank ...
 
#7 ·
@marathonman you're recordings may have been slightly off with the method used. But your speedo will be out by a static percentage value. So if it's overstated by 14kph at 100, at 50 it'll be over by 7.
If you go the electronic method for correction, Healtech is the major brand in that department; model number SH-H05 is for our bikes.
If you go the sprocket change method, the website gearing commander will assist in your calculations.
 
#11 ·
Time for new tires. There's no other reason for your speedo to be that far off. My bike has been bang on with the GPS as well as the "What's your speed?" radar stations near me until recently. I'm just over 5k miles on my tires and I'm starting to see a 1 to 2 mhp difference at ~50 mph now. I expect this margin of error to grow ever more quickly as I add miles to the tires. I kind of like it being overstated a little. It helps to keep me law abiding sometimes.
 
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