Auto gearing

[jimboalee]

I have just heared off an old friend at a Research institute I once worked at.

They have a recumbent with an ATC NuVinci Variable gear ration hub operated by a stepper motor.
The rider's cadence is measured and a small ECU sends signals to the stepper motor to adjust the gear.

Program in 90 rpm and the ECU adjusts the ratio so you always pedal at 90 rpm, up hill or down dale.

I have asked for a test ride,,,

 

[Steve Austin]

What happens if you pedal at 85rpm?

 

[jimboalee]

Dooh!

Knowing the guy who has built the thing up, it will be a trimpot ( he loves trimpots ).

My guessing is you ride along and twiddle the trimpot until the ECU is controlling to your favourite / natural / desired cadence, displayed on the bike computer.

When you're happy, you lock up the trimpot.

 

[Yorkshireman]

Speaking (as it were) of auto geared bicycles ...
http://members.lycos.co.uk/fiultra/BICYCLE Trek Navigator L700 Smover.html