Speed mismatch Kiox and GPS

[gunshot72]

Got a 2.5 kmh difference between the bike and my Hammerhead GPS meaning I reach assistance cut off too soon! The Hammerhead is very accurate on speed. Is there a fix either easy or hard? I don't want to delimit the motor as the bike is only 2 days old!

 

[Doomanic]

Get your LBS to alter the wheel circumference.

 

[Davidwylie]

Get your LBS to alter the wheel circumference.

You can change the wheel size yourself in the Kiox setting menu. Just set the wheel a couple of points smaller have a test ride over a measured distance. Keep adjusting until you get as close as you can to your GPS. Took a bit of messing with mine, sometimes my GPS and Kiox are spot on, but on the same route on different days there still can be a small discrepancy, but its tiny, never going to be a perfect match.

 

[gunshot72]

Thanks for the replies but I don't think changing the wheel circumference works. I tried it and there's no difference. I guess wheel circumference is just for measuring distance travelled.

 

[Davidwylie]

Thanks for the replies but I don't think changing the wheel circumference works. I tried it and there's no difference. I guess wheel circumference is just for measuring distance travelled.

That is about as accurate as you are going to get. It is impossible to get the speed of your GPS and Kiox to match. You are never going to be able to pedal at a constant rate for long enough, the bosh system sensors check reading hundreds of times a second and the speed is never constant, every slight undulation in the road surface changed the speed. GPS speed is not effected buy your pedal stroke, it measures how long you have taken from one point to another and calculates speed. They will never match exactly, but at the end of your ride, top speed and average speed should be about right and match on both systems. If your wheel size is correct and you can ride a measured mile and get 1 mile on your display then that is right.

 

[Philpug]

My Kiox is about 10% off from my Strava. When the bike says I did 15 miles, Strava shows 13.5

 

[Davidwylie]

My Kiox is about 10% off from my Strava. When the bike says I did 15 miles, Strava shows 13.5

Reduce the wheel size in the Kiox setting menu

 

[Krakaride]

Dab paint on one of the centre tyre knobs, sit on the bike and roll out the wheel on a flat surface in a perfect straight line until you have both paint markings on the floor. Measure the distance between the two markings, accurately to the millimeter and enter that value into the wheel circumference setting in KIOX. KIOX will be as accurate as possible now.