Off-topic: Dirt-simple 1903-technology two-speed bicycle

Drivetrain

Some footbikers might be interested in this; I got into footbiking as a bicyclist with a simplicity fetish, and have continued using a single-speed bicycle for some tasks.

But when I found this, the idea captured my attention strongly. It’s a two-speed bicycle-gearing system, brought to its present state in 1903, but simplicity itself.

Retro-direct gearing uses no levers or cables, just two independent freewheels and a chain-tensioner. The chain is routed from the chainwheel to one freewheel, looped around the chain tensioner and back to the other freewheel in such a way that one gear is accessed by pedaling forwards, and one by pedaling backwards.

As I studied pictures of antique and modern bikes using it, Arthur C. Clarke’s Third Law came to mind: “Any sufficiently advanced technology is indistinguishable from magic.”

As to the mechanics, two single-speed freewheels were joined using an old bicycle bottom-bracket cup (which has the same threading as the freewheels), and a KORE chain tensioner was deployed near the crankset. That’s it, except that I joined two chains together to reach the necessary length.

Like some other modern adherents, and contrary to the traditional setup, I use the forward-pedalling gear for my lower speed (for starting out, tooling around and hill-climbing) and the reverse-pedalling gear for higher-speed cruising. Pedalling backwards is bringing new muscles into play; I feel it in the back of my thighs, but choosing between two gears is pretty intuitive otherwise. (I’ll see if the development of these muscles brings anything to the footbike.)

I live where the Wright Brothers came to fly their aeroplanes; one reason they chose the Outer Banks was that these barrier islands are quite windy. The main roads run roughly north and south, and one often pedals or kicks against a 10-25-mph wind or with it. With the footbike, it’s pretty easy to deal with the wind, less so with a single-speed bicycle, if you have limited patience with derailleurs, cables and levers.

N.B. If your pedals are not more-or-less frozen to the cranks like mine, add some Loctite to ensure they don’t unscrew while you’re pedaling backwards.

Okay, the next ‘blog entry will be about footbikes, I promise.

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3 Responses

  1. Peter—-That is the weirdest darn thing I have ever seen. I swear I thought I had delved into every type of gizmoflizmo setup I could find! This is awesome! I am heading into the shop right now to check out the parts bin. Just don’t tell my footbike that I am doing this…..

  2. Tell me about it! Been cycling since the 1970’s and never had a clue about it until the good old internet! Of course it’s not going to make a dent in my footbiking, but when it’s raining or snowing (which it does here once every few years) it’ll give me a cool way to deal with wind and hills…

  3. non c’est le scooter qu’on veut !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

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