On Mon, 8 Oct 2007 19:18:40 -0800, "Paul Borg" <[email hidden]>
Quoted message said:I want it to go forward when I pedal counterclockwise.
Thanks
Dear Paul,
Assuming that you mean going forward by pedalling backwards rather
than the ambiguous counterclockwise, it's actually possible.
Retro-direct bikes had two speeds, one when you pedalled forward,
another when you pedalled backward:
http://en.wikipedia.org/wiki/Retro-Direct
Plenty of nice links, which eventually let you see how it works. This
site may have the best picture angles and description for how the
chain works:
http://www.m-gineering.nl/retrog.htm
(And it also happens to be the site of frequent RBT poster.)
If you want to settle for a mere single-speed, you just twist a half
loop in the chain, making some kind of adjustments to clear the chain.
The Wright Brothers twin-prop airplane did this:
http://www.first-to-fly.com/History%20Images/1905%20Flyer/Looking%20forward%20s.JPG
It's hard to see, but the enormous chain drive to the pilot's
left-hand prop goes through metal tubes, which you can see crossing
to his right. This let the drive shaft spin the props in counter
rotation.
Here's the rest of the Wright site, with lots of pictures:
http://www.first-to-fly.com/History/Wright%20Story/mccoy.htm
Cheers,
Carl Fogel