shaft-driven bicycle hub

I was sitting in a dentist’s office waiting for the Mighty Wife to get her teeth cleaned when I saw an article in a magazine about a chainless bicycle. It was being sold as a luxury item, the outstanding selling point being that it had no chain. Big Whoop. Now a chainless giraffe unicycle, that would be big news; I looked up the website where the bike was being sold[] and read the advertisment.[search word: chainless] The thing had gears and the hub was made by Shimano. Such a setup on a giraffe would make an undershaft shock absorbsion system possible and also eliminate play in the chain. No, I don’t know if it would work or not, but if any of the frame builders want to kill some time this would be a bomb project if successful. carjug

That’s really interesting. It does seem like it’d work for a giraffe doesn’t it. Maybe it wouldn’t be as smooth when changing from pedalling forwards to pedalling backwards.

I don’t know what I’m talking about.

the reason it’s never worked on bikes yet is the efficiency of power transmission. On a giraffe that wouldn’t be too much of a problem, however you’d still have backlash, probably a fair bit more than on a good double chain giraffe.


Back in Oct./Nov. I found a website that had a 2 wheel drive mt. bike and contacted the owner, Gene Spicer. See

Gene, btw is also a unicyclist. He said the current system was only designed to operate in one direction and it was a flexible cable and not a shaft. A shaft driven giraffe would have to be custom built. I put the project back on the shelf. As as long as my chain-drv MUni giraffe is still working fine, I am in no hurry to replace it.

I envision a shaft-driven setup much like an old gear-driven eggbeater. Refer to the following illustration.

Engineering is not my forte, but I do get visions. That’s how I ended up in MUni in the first place. Wouldn’t it be cool to design a telescoping shaft that could position itself to fit various sized gears? You may end up with a gear-change-on-the-fly type machine.

More food for thought.


  • Scot

"The future belongs to those

who believe in the beauty of their dreams."

  • Eleanor Roosevelt (1884-1962)

I wonder how much trhose 2wd bikes weigh. I would’ve thought that the disadvantage of extra wight would cancel out the advantage of having 2wd. Just to bring it back on topic, would a system like this add too much weight to a giraffe? I’ve never ridden a giraffe so I don’t know how important weight is.