Reversed Bike Gears?

January 15, 2007 10:12 AM

Is there a bike that can be pedaled backwards?

I was recently talking with a close friend who has a grandson with a degree of cognitive impairment which manifests itself in an apparent inability to perform certain physical tasks. In this particular case, her grandson has an inability to correctly pedal a bike, pedaling in reverse, instead of the normal forward pedaling.

I figured some of you brilliant bike mavens might know of an unusual bicycle or perhaps somewhere that could modify an existing bike so they can go riding together this summer.

posted by Samizdata to Sports, Hobbies, & Recreation (16 answers total)

A unicycle?
posted by jourman2 at 10:15 AM on January 15, 2007

A fixed gear track bicycle?
posted by jaimev at 10:18 AM on January 15, 2007

yes, a fixed gear can be pedaled backwards. However, it sounds like you are looking for one that will go forward regardless of which direction the pedals spin, correct?
posted by caddis at 10:18 AM on January 15, 2007

third to the fixed gear. I have one. They are super fun. If you pedal backward too hard, bad chain mojo can happen, though.
posted by YoBananaBoy at 10:29 AM on January 15, 2007

Actually, you can put a fixed gear hub on any bicycle. It would require a weird custom wheel/hub and some silliness with the chainline and whatnot, but it would be possible.
posted by YoBananaBoy at 10:31 AM on January 15, 2007

I think it's pretty obvious from the way the question is phrased that she does not want this boy pedaling such that the bike actually moves backwards.

Rather, the boy intuitively pedals backwards, but wants to go forwards, and she wants to know if there is any bike that operates this way. Is that right?

I don't know of any, off hand. I would imagine that there is a mechanical disadvantage to it, which is why I wouldn't expect there to be any such bikes.
posted by RustyBrooks at 10:46 AM on January 15, 2007

Best answer: Such bikes do exist. Basically they allow you to pedal in either direction, and the drive train translates the pedal motion into forward movement. Some bikes were manufactured using this odd drive train, but as the first link shows it is possible to retrofit a modern bike to do the same thing.

Googling "retro-direct" brings up more, including a Wikipedia entry with a gear diagram. If you don't care about being able to pedal forward at all, you could probably make the gearing simpler, but I'm not enough of a bike nut to figure out how you'd modify a bike in such a fashion.
posted by chrominance at 11:11 AM on January 15, 2007

Response by poster: Yes, I need the bike to go forward when pedaled in reverse. There shouldn't need to be any allowance for forward pedaling...
posted by Samizdata at 11:24 AM on January 15, 2007

How about that. There is such a critter, sort of. It's called Retro-Direct, and it uses reverse pedaling for 2nd gear (on a two-speed setup). It's not in current production but judging from some of the articles on the linked page, it's not that hard to jury-rig.

There's another type of bike drivetrain where the rider uses a stepping motion rather than pedaling (this is also variously called linear or reciprocating drive). Bikes built on this principle have been built from time to time for years, though not in great quantity. There's really nothing to get backwards on this, so this might be another possibility. Here's a page listing several such bikes (scroll down about 1/4 to the "drive systems" section).
posted by adamrice at 11:26 AM on January 15, 2007

Best answer: This one is a bit simpler than the one linked by chrominance. It uses two BMX freewheels, one for forwards, one for backwards. The only tricky bit is you need a chain tensioner mounted more or less under the bottom bracket. The one in the link has a brazed-on chain tensioner, but I imagine you could probably hack something together with some hose clamps and an old rear derailleur.

I was meaning to put together a bike like this last year, and never got to it.
posted by Lazlo Hollyfeld at 11:28 AM on January 15, 2007

Could you maybe take a standard bike and just install the chain in a figure-8? I know there would be a heck of a lot of friction where the chains cross (so you might need a small sheet of delrin/nylon/whatever to keep them from rubbing) and the chain would probably not last very long due to the extra strain, but it might get you close enough.
posted by Rhomboid at 11:51 AM on January 15, 2007

Beside the fact that they exist, I know very little about shaft-driven bikes. Would there be some way to tweek them to get backwards pedaling to result in forward motion?
posted by ObscureReferenceMan at 12:34 PM on January 15, 2007

Sounds crazy, but perhaps the child could ride in the rear (stoker) position of a tandem bike and gradually learn forwrad pedalling?
posted by fixedgear at 12:54 PM on January 15, 2007

ellyptical machines can do this, too.
posted by krautland at 2:53 PM on January 15, 2007

Best answer: There are some community groups, like Bicycle Inter-Community Art and Salvage that will provide tools, parts, and help learning how to fix your bike. As that link says,

We don't do repairs for you (a temporary solution), we help you fix your bike (an empowering opportunity).

You can fix your bike at BICAS by using our tools and choosing from our selection of used parts. And don't worry, we will be there to help you along the way.

Perhaps finding a local chapter of this group, or a similar one, would help you out. Try contacting them and explaining your situation. Maybe they would waive the "We don't do repairs for you", in the case of a unique project that would help out a child with a disability.
posted by white light at 6:07 PM on January 15, 2007

Response by poster: Thanks for the tips all.

Now, off for research...
posted by Samizdata at 8:53 AM on February 4, 2007