The first AutoBike automatic transmission works like this:
- The rear wheel had three weights mounted on it, which, as the bike accelerates, would move out radially against springs
- By a system of cables, these weights moved a disc near the centre of the wheel outwards
- This disc engaged with the small roller mounted on this Autobike derailleur, moving outwards, in turn
- The derailleur, in its turn, moves the chain across the freewheel sprockets.
It's crude, it's nasty, it used a lot of fragile plastic parts - and it was soon renamed 'Classic' and effectively replaced by a more integrated design. Just to reinforce my point, this particular example has a broken roller.
But none of this addresses two fundamental problems:
- Firstly, the gear a rider requires does not correlate that well with rear wheel speed
- Secondly the sytem was not indexed - so it was more than possible for the speed of the bike to determine that your ideal chain position was exaclty in-between two sprockets.
- Derailleur brands: AutoBike, manufactured by Falcon
- Country: USA, manufactured in Taiwan
- Date of introduction: 1995?
- Date of this example: unknown
- Model no.: unknown
- Weight: 293g including hanger plate, but with a broken roller and none of the terrifying mechanism that attached to the rear wheel.
- Maximum cog: 28 teeth?
- Total capacity: 28 teeth?
- Pulley centre to centre: 56mm
- Index compatibility: friction
- Chain width: 3/32”
- Logic: low normal
- B pivot: sprung
- P pivot: sprung
- Materials: steel