http://www.recumbents.com/wisil/tetz/e-assistmetric/
Bents only I suspect because it uses the idler.
"My assist philosophy has been based on the concept of truly low power
giving just enough assistance.
This allows for a lighter weight system such that when the assist is
not in use it doesnt detract from the overall efficiency of the
vehicle/rider combination. This means the low assist weight requires
very little additional energy from the rider when climbing or
accelerating (a lightweight vehicle also helps).
My design goal was around 100 input watts to the motor and less than
10 pounds total system weight. It came in at 4.2 pounds, 1.9kg ! --
Thats every thing motor/gearbox/freewheel/mounting bracket assembly,
battery, electronic controls.
The numbers (speeds and power) you will see throughout this report
will be quite low for many HPV enthusiasts. But what I am designing
for is not so much for speed but for reduced effort from the rider. Im
mainly designing for local alternate transportation and for more
average people - people who simply dont have the power capabilities
and need a little help. They would include smaller people, women, and
us older folks. The rider pedals all the time but at a more
comfortable level where both the rider and assist are combined and the
power from each is somewhat similar. This fits with a definition of
true assistance"
It is not, of course, in production. Sigh.
I don't know if I'd use it, but I think I'd like to try it. Speed up
the commute a bit, and encourage me to go further afield instead of
using the motorbike.
Zebee