My friend Mike has a steel rod instead of bone for his left leg; no knee at all. He's been looking for an "automatic" solution, as he doesn't like the Pingel setup he has now. We rode over to the area Ridley dealer to see their bikes. Overall, the bikes weren't bad, they had their own engine and drive train. All the components were mid-priced aftermarket "Harley" stuff. They let us test ride a couple.
The automatic bike was really weird to ride. You open the throttle, the engine goes almost instantly to full RPM, and then the bike "catches up" to the engine. Top speed was a bit over 80. Stopping was really strange too; you chop the throttle and the bike just keeps going. Brakes only.
I don't think I'll be looking for an auto any time soon. I don't like them in cars that much, and I sure don't want one on my bike. Did you know that only 15% of the US driving population can drive a car with a clutch? That number astounds me.