Retro Direct gearing

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I have been holding this back thinking I would find the parts and bike to complete this project. But I havent had the time or finds.

Here are some links that explain it. But basically you pedal backward for low gear and forward for high gear. Two bmx freewheels are cobbled on the rear wheel and the chain is routed over the top of both down to a tensioner pulley.

Retro-Direct.jpg


http://www.frankb.us/gears/
http://bikerodnkustom3.homestead.com/Li ... irect.html
http://en.wikipedia.org/wiki/Retro-Direct

I expect Hooch or Chainsaw to try this first.
 
An idea for you. What if you had chainrings on each side and sprockets on each side, one backwards in one gear, the other forward in your other gear. Edit: just realized that wouldn't work, never mind.
 
That's is a very smart and creative idea. Really cool. My only concern would be damaging my knees pedaling backward. I'd love to see someone build it.
 
Mid-Drive / Under-Over Drive

Here is the mid drive I use on my 26/20 low racer

image004.jpg


To Build my mid drive I took one of the following freehub (the left 2 should work).

image006.jpg


1) I removed the internal locking sprags for it.
2) I then took the cassette and file out the small splines, so I could mount the cassette on backward ( the smallest sprocket towards the inside of the freehub)
3) Thread on the BMX Freewheel on the outside of the Freehub

image008.jpg


4) find a way to mount this on your ride ( I used one of the arms off of a ten speed, you could use both sides to make the free hub removable easier)

The advantage to this is that it will give you a super underdrive (major granny gear) as well as a mega overdrive for the down hills


Here is a friend of mine (Scott) posing on my 26/20 lowracer

image012.jpg



I you have any question please let me know.

Doug
 
I bought 2 bmx freewheels this afternoon, and the shop owner gave me a
used bottom bracket cup that should work for connecting the freewheels.
I'm thinking that if I use a BIG big ring and fasten some BIG cogs to the bmx
cogs I can create a radical enough chain angle to avoid needing to alter
the chainstay????? If that doesn't work I may add another jockey wheel to
avoid the chainstay mods. Next I have to go to the bike pile and select a bike
.......hmmmm........diamond frame????????.......tandem?????......
Jerry
 
Jerry thanks at giving this a try. The frame mod would be nice to get around. For ease of install and in case you want to go back to original.

Keep us posted
 
Check out the retro direct here.

http://www.blackbirdsf.org/randonneuring/2007_pbp.html

The pbp is a real hardcore ride. On a 1920 retro-direct bike it would
be a challenge beyond description.
I selected a 27 pound diamond frame ten speed from the pile
today and removed most of the excess parts. I even found a ratty
way to recycle the clamp on down tube shifters. Here is a hint : Do
any of you remember a product called "Flickstand"?
Jerry
 

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