Not to crazy about the look, there are skulls everywhere now, and I'm not sure why. But we do need a quality failure proof tensioner, one several times stronger than what is absolutely necessary, and that does not clamp onto any part of the bikes frame. Ideally the bike frame would have a super heavy duty steel mount welded on, and the tensioner would bolt to that. It would need to be adjustable, like a derailleur, so it could be lined up perfectly with the chain. And it would need to be under constant spring tension, so it would move with the tight and loose spots in the chain, keeping constant tension on it. I would like to see a steel sprocket, that fit the chain, running on high quality bearings. The basic design of a derailleur would seem close to what is needed, just bigger and much stronger, for the motor driven chain. Such a device is certainly possible, most would object to it's cost, but having almost been killed by one of those Chinese POS things (crashed inches from 45 mph traffic) I would not. Motorized bikes have long needed much higher quality components. Parts that fit without cutting and drilling and shimming, basically rigging things to try and make them fit the bike. I don't know of any statistics on the matter, but I have to wonder how many people have been killed or seriously injured when they rigged a Chinese engine kit to a Walmart bike with cheap wheels and only a rear coaster brake.