Retro Direct Drive

Two gears and no shifting; perfect for people that can't think about shifting gears. In fact I have a hard time remembering which way to shift down sometimes because I have two bikes with friction shifters; both in opposite directions.










 Retro-direct was developed by French inventor Paul de Martin de Viviés
(1833–1911).     http://en.wikipedia.org/wiki/Retro-direct I think it was meant for a 60degree seat tube

Building a Retro-Direct Drive Bicycle
 http://kentsbike.blogspot.com/search?q=retro+direct

                                           http://sports.groups.yahoo.com/group/retro-direct/




more odd drives:
http://en.wikipedia.org/wiki/Bicycle_drivetrain_systems

Shaft Drive
This one would be good if it works right, but unless it is in an oil bath, dirt will distroy it.

http://en.wikipedia.org/wiki/Shaft-driven_bicycle

http://www.beixo.eu/en/_cardanas

http://en.wikipedia.org/wiki/File:2011-04-07-birdy-by-RalfR-01.jpg