I don't know the exact Torq frame size, but it's best for taller riders, I could only just manage it at 5' 6". The Wisper frame is the opposite, well suited to smaller riders but I don't think for over 6' as others have also said.
Almost none of the hub motor bikes is fully suitable for rough off road conditions, and many including the Torq warn of this in the manuals or elsewhere. Hub motors have hollow spindles to carry the cables in, strong enough for road shocks, but possibly not for off road, although front suspension will allow the wheel to rise away from a bump and ease the shock.
The other consideration is the battery weight, near the rear usually and taking shocks direct from the rear wheel. I've in fact suffered a smashed battery carrier platform on an e-bike, caused by a near vertical edged speed calming platform.
Rear suspension could ease this of course, but the only e-bikes fully suitable for off road are odd ones that have central motor and battery and dual suspension. Lot's of people use e-bikes, including the Torq, on sustran tracks and the like, and when not too rough that's ok of course, seeing that some of our roads can be worse.
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