Bosch Purion - Tire Size Setting - Odometer and speed display when changing tires

[SJC]

My buddy and I both own Trek Powerfly 4s (his is 2021, mine a 2020). Both our bikes run Bosch motors and Purion controllers. In advance of a longish road ride, we each swapped out the stock 2.3" mountain bike tires for Schwalbe road tires. He went for a 60mm tire and I went for a 50mm. The sidewall on his tire is taller than mine, so effectively his wheel diameter is larger than mine. As a result, my bike displays speed and distance covered as approximately 10% greater than his, even though we ride the same actual speed and same distance.

Question, is there a way to adjust the Bosch Purion controller to take into account different tire sizes in calculating speed or distance?

(Apologies if this question has been asked and answered. I searched but could not find it.)

 

[Deleted member 4845]

Usually settings give small increments for wheel size, unfortunately they often do not identify exact increments used. If possible, reduce wheel size setting by approx 10%. If settings are not available, or increments not small enough, you could either get an aftermarket speedo or else learn to live with it.

 

[SJC]

I cannot find access to settings. My Trek bike uses a Bosch Purion system. If anyone knows how to access settings, I would love to hear from you.

 

[Deleted member 4845]

Read your manual or call your dealer. You paid extra for this "feature".