This is the "chain disconnector" (for lack of a better word) that I made for the chain that connects the electric assist motor to the left-hand side chainwheel. When I want to ride in silence and without extra drag from the secondary drivetrain, this device disconnects the chain from the chainwheel entirely.
It works with an old rear derailleur mounted in reverse, a custom-made derailleur hanger that clamps onto the front boom, and a heavily modified oversized plastic pulley to hold the chain in its resting position.
Finally I can ride my velomobile in total silence when I don't use the motor!
