This patent describes the Campagnolo Corsa, a nightmare system of beautifully chromed rods attached to your chain-side seat-stay. It works something like this:
- First you drop out of the peleton so that you do not cause a catastrophic pile-up.
- Then you twist the top lever. This slakens off your rear quick release.
- Then you fiddle around with the lower lever while back pedalling in a hopeful attempt to force the chain onto the other of two sprockets that you have on your hub.
- Then you pedal gently forward to 'position' the rear wheel.
- Then you twist the top lever back to its original position to relock the quick release.
- Then you sprint like crazy to try to get back onto the rear-most wheel of the peleton.
Di2 it ain't.