Wheel size and tyre circumference on a Shimano STEPS SC-E6100, SC-E7000 or SC-E8000
Wheel circumference is not in the display menu and not in the consumer E-TUBE app. It is a drive-unit parameter that a Shimano dealer changes with E-TUBE Project in dealer mode. If the speed reads wrong after a tyre change, this is the fix.
Step by step
- Check first whether you really need it: compare display speed with a GPS app over a flat kilometre. A difference of 1-2 % is normal tyre wear; 5 % or more points at a wrong circumference.
- Measure the real circumference: mark the tyre, roll one full turn with your weight on the bike, measure in mm.
- Open E-TUBE Project on your phone and connect. Under the drive unit you can view the current circumference, but the field is read-only for consumers.
- Take the bike and the measured value to a Shimano STEPS dealer. They log in to E-TUBE Project in dealer mode, open the drive unit settings and enter the new value.
- Ride a known stretch and compare with GPS again.
Can't find it?
Dealer says the value is locked: on some OEM bikes (Cube, Trek, Merida) the manufacturer locked circumference entirely. Only that brand's service centre can change it.
Frequently asked
Why can't I change wheel size myself?
Because circumference determines where the 25 km/h assist cut-off happens. Shimano treats it as a type-approval setting and keeps it in dealer mode.
My speed is 10 % too low after fitting new tyres. Is the sensor broken?
Almost certainly not. A different tyre width changes circumference and the speed reads off. Have the dealer enter the new value.
Does E-TUBE Ride show wheel circumference?
No. E-TUBE Ride is ride data and assist profiles only. E-TUBE Project shows it, but read-only in consumer mode.
Manuals and video
Videos found on YouTube and checked automatically; they are other people's work, not ours.
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