What happens if you run a 27.5" speed calibration on 29er wheels

[2WheelsNot4]

As in you calibrate it for 27.5" wheels, but instead of fitting 27.5" wheels, you keep the 29ers on it.

Do you go faster ?
I would think the sensor setting would measure the 29er or 27.5er as diameter, revolutions etc to calculate the speed. X number of times the magnet passes the sensor type of thing, as not all are linked into the phone/bluetooth GPS. So it has to measure its speed somehow.

 

[Brent8275]

You'll go faster, however the speedo will be incorrect (shimano has a correction factor you can apply to the display to adjust this however)

I suspect that mine is calibrated for 29 but I only have a 27. 5 so my max assistance true GPS speed is just over 28km/hr.

 

[urastus]

Assistance will stop sooner. You will

shimano has a correction factor you can apply to the display to adjust this however

+ or - 5%. Note; it only changes the displayed speed by -5 or +5%. If you choose -5% assistance will stop at 23.75km/h (if limited to 25km/h). This change won't be reflected in the logged speeds and distances etc.

Also the odometer will be out of whack with the 29" wheels - it will record less km than those travelled. Only an issue if you use the odo for service intervals (as I do). An equation could be easily figured out to find what the real distance travelled is, although my bike is not correct anyway - it records faster than I'm actually going and therefore also records more kms travelled.