http://en.wikipedia.org/
I had an old threaded Mavic rear hub with a 70s Suntour freewheel (threa ds all the way through the body), a bottom bracket cup threaded into tha t freewheel and hub, and another freewheel on the outside of the BB cup.
It put two freewheels on the back hub. The wheel got destroyed in my las t move, so I never got a change to rig it up on a frame and ride it.
Steven Johnson, Shiloh, IL
It was something called a "retro-direct" system and many Hirondelle bike s
used it from 1924 to just before WWII. A couple other French manufactur ers
produced similar derailleur and chain systems including one named "Le Cr ack"
(yes, really). They are mentioned only very briefly in "The Dancing Ch ain", but
I can't figure out how they work. In the book it shows a double pulley
device mounted just behind a crankset which had TWO chainrings - though I see
only one on the PBP bike. So, I guess you'd have two speeds in the bac k and two
more up front... that is, unless the chain routing somehow multiplied t he
possible number of different gears you might achieve?
I'd sure love to see that Rube Goldberg chain routing in action!