What about unsprung weight? That would be a real drawback on a performance bike.Mr. Dazzle wrote: ↑Wed Mar 09, 2022 8:52 pm The reason you see it on scooters is simply down to power...a 5kW motor isn't very big. You can get a 50 or 150kW motor which fits inside a hub, but that's right out there ATM.
The other thing I'd suggest is that we're familiar with the rear wheel mounted engines on a typical scooter, so a hub mounted engine doesn't look as weird as it does on a motorcycle where riders expect the 'engine' to be under the 'tank'.