Originally Posted by
ephemere
Is most excessive chain wear from mid-drive e-bikes due to shifting (under load while powered)? Or due to increased wattage coming out of the cranks while in a fixed gear? Or both?
Papa Ado?
If the vast majority is due to shifting under powered load, then that means I can prevent excessive chain wear by optimizing shifting technique.
(I'm approaching 300 miles on my first e-bike and will measure chain stretch with a caliper tomorrow. But most of those miles were with the motor off.)
Shifting will put more lateral stress on your chain so pin power is important here. Simply be careful when shifting under (mid motor) load since tensile stress is highest between cassette and chainring; improper shifting (timing, RD operation, etc) will result in the chain not setting in time and thus twisting over the top of the cassette.
As others pointed out, chain wear primarily comes from load through the chain - increased force will increase wear.
You mentioned the majority of your distance is ridden with the motor off. Is this common practice?