To Lowell: The bicycle part of the drive train took the strain of the the engine (and pedaling simultaneously) just fine. Never broke a chain.
To Torque: The photos may have made it look like "a mess" as you say, but it reality it was an elegant design.
To my knowledge, I was the first person to invent the pull-through spring style suspension that you see on this bike. Since then, other mainstream mountain bike manufacturers have employed it. This bike had no discernible "pogo" when pedaling, yet rode like a Cadillac. Big bumps at 30mph were a non-issue as they should be with a motorcycle. The gearing was excellent. 25 gears for pedaling (5 in the rear x 5 at the jackshaft) and 5 gears for the motor. Lots of fun to accelerate up through them. The weight of the motor was low and noise was reduced by virtue of the motor being located behind the seat. It was a joy to ride and I actually looked forward to the daily commute to downtown Seattle. With the engine off, it was fairly high performance recumbent.
I'm not a huge fan of recumbent bikes but if somebody could find a way to easily (or fairly easily) drive engine power through a bikes normal gears while allowing the pedals to freewheel I'd be sold in an instant. One of the only things I'm not satisfied about with HT engines is the nonexistent low-end torque. But let a 50cc engine scream in low gear on a 21+ speed mountain bike and you have a thrilling off-road ride, as well as on-road high top speed.
In any case, that bike looks comfy and fun as heck!