Home › Display settings › Yamaha PW displays (Display A, Display C, Interface X, Display X) › Yamaha PW displays: wheel size (dealer / diagnostic tool)
Wheel circumference on a Yamaha PW e-bike (Display A, C, X, Interface X)
Yamaha keeps wheel circumference in the drive unit. It is set by the bike manufacturer and changed with the Yamaha dealer diagnostic tool; no display or consumer app offers it.
Step by step
- Check with GPS whether speed is off by more than 5 %.
- Measure the rolling circumference under load in mm.
- Take the bike and value to a Yamaha or bike-brand dealer; they enter it with the diagnostic tool.
- Verify with GPS afterwards.
Tip: A 27.5 to 29 or a wide-tyre swap changes circumference enough to notice. Plan the dealer visit together with the tyre change.
Can't find it?
Dealer cannot change it: some bike brands (Giant especially) lock the value to their own service network.
Frequently asked
Is there a hidden menu on Display C for wheel size?
No. Older forum posts describe one on early PW displays, but current firmware does not expose it.
My speed reads wrong, is the sensor faulty?
Check magnet-to-sensor gap (2-5 mm) first, then circumference.
Does the app show wheel size?
The Yamaha app shows nothing about circumference.
Manuals and video
Other Yamaha PW displays (Display A, Display C, Interface X, Display X) guides
Yamaha Display A / C / X: switch mph to km/hYamaha Display A / C / X: reset trip distanceYamaha PW: assist modes and what you can (not) customiseYamaha Display X / Interface X: pair with the Yamaha e-bike appYamaha PW: firmware update (dealer, app on newer models)Yamaha PW: walk assist (push assist)Yamaha PW displays: lights on/off
Still stuck? Take a photo of the display and show it to a local e-bike workshop. Bring the bike's system name (e.g. Bosch Performance Line CX) and the exact code; that saves diagnostic time and money.