Notice anything odd about this bike? If you’re looking at the unusual drive-chain then you’ve spotted it. The retro-direct system is a two gear system that has no need of shifters, derailleurs, or geared hubs — just pedal backwards past the break for details on how you can make your own…
What appears to be an out-of-place derailleur or chain-tensioner is actually the retro-direct’s jockey wheel redirecting the chain-line back to a second freewheel.
What’s the point? Pedaling forward engages one freewheel, pedaling backwards engages the other. Voila, two gears!
While earlier designs existed prior to the 20th century, it was the French bicycle manufacturer Hirondelle who supposedly patented this single chain retro-direct drive in 1903. Naturally, once the derailleur and internally-geared hub came about, the retro-direct fell from favor.
But what was old is new again. And while he’s not the only individual to resurrect the retro-direct, Scott Mayson has used 3D printing to take it one step further, making it possible for anyone to follow in his retro resurrecting footsteps.
Mayson documented the development of his own retro-direct system here. Using a steel frame from the 80’s he fabricated and mounted the 3D printed jockey wheel. A handbuilt rear wheel with two differing freewheels (17t and 22t) completed the retro-direct drive system.
If you wanna stand out at the next pub crawl or Tour de Fat, or if you just like what you see, head over to Scott’s order page here and follow his instructions for getting your own custom 3D printed retro-direct jockey wheel.
