It's not hard to find e-bikes with belt drives. Honestly, I think they'll take over the e-bikes market within 10 years or so (I think there are still some outstanding patents?). More expensive and slightly less efficient than a chain, but both of those are probably negligible for the context of e-bikes, and in exchange you never get grease on your pant leg, you never need to lube anything, you never need to worry about a derailleur needing to have its gears realigned or having the chain jump out (of course you could have an internally-geared chain bike).
Harley Davidson, among others, uses belts. Torque isn't the issue in the context of m/c final drive. Chains are a tad more efficient, which hp obsessed customers fuzz about.
I have a lectric and the build quality is terrible. Had to deal with:
- a bent frame out of the box
- a recall due to defective brakes
- lights not secured properly
- loose fender after less than 100km
- a derailleur that refuses to allow use of all gears- no matter how adjusted it is unable to use either the lowest or highest
