Yes, I saw the worm drive, fits with the bike though since that sort are inefficient anyway.
I wouldn't use a bike like this on the road, but with the high ground clearance, strongly cased motor and battery protected by suspension it would be good for rough ground off road fun.
I didn't look at the video so didn't realise there was no freewheel in the gearwheel, but there's a way out of that by using a Cyclone freewheeling chainwheel.
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