Oh man. Allen. That visual is killing me. image

The "emissions" from the terrier might not be a good selling point either. image

But seriously, I think there are a few good ideas here.
I was thinking about an electrical charging braking system similar to what they use in the hybrid cars.
And you are right, half the trip is usually downhill.

The next generation of batteries will likely make a few of these ideas quite viable.
They really need to break into the 150 - 200 mile range before I'd be comfortable cruising in the mountains.

I'm still rolling over the "gyrocopter" approach. Too funny.
At the very least it should reduce helmet weight and head wobble.