Comments on: Reversed Bike Gears?

Question: Reversed Bike Gears?

Samizdata — Mon, 15 Jan 2007 10:12:01 -0800

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.

By: jourman2

jourman2 — Mon, 15 Jan 2007 10:15:02 -0800

A unicycle?

By: jaimev

jaimev — Mon, 15 Jan 2007 10:18:03 -0800

A fixed gear track bicycle?

By: caddis

caddis — Mon, 15 Jan 2007 10:18:35 -0800

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?

By: YoBananaBoy

YoBananaBoy — Mon, 15 Jan 2007 10:29:53 -0800

third to the fixed gear. I have one. They are super fun. If you pedal backward too hard, bad chain mojo can happen, though.

By: YoBananaBoy

YoBananaBoy — Mon, 15 Jan 2007 10:31:45 -0800

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.

By: RustyBrooks

RustyBrooks — Mon, 15 Jan 2007 10:46:40 -0800

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.

By: chrominance

chrominance — Mon, 15 Jan 2007 11:11:49 -0800

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.

By: Samizdata

Samizdata — Mon, 15 Jan 2007 11:24:58 -0800

Yes, I need the bike to go forward when pedaled in reverse. There shouldn't need to be any allowance for forward pedaling...

By: adamrice

adamrice — Mon, 15 Jan 2007 11:26:22 -0800

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).

By: Lazlo Hollyfeld

Lazlo Hollyfeld — Mon, 15 Jan 2007 11:28:47 -0800

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.

By: Rhomboid

Rhomboid — Mon, 15 Jan 2007 11:51:51 -0800

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.

By: ObscureReferenceMan

ObscureReferenceMan — Mon, 15 Jan 2007 12:34:26 -0800

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?

By: fixedgear

fixedgear — Mon, 15 Jan 2007 12:54:26 -0800

Sounds crazy, but perhaps the child could ride in the rear (stoker) position of a tandem bike and gradually learn forwrad pedalling?

By: krautland

krautland — Mon, 15 Jan 2007 14:53:13 -0800

ellyptical machines can do this, too.

By: white light

white light — Mon, 15 Jan 2007 18:07:51 -0800

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.

By: Samizdata

Samizdata — Sun, 04 Feb 2007 08:53:54 -0800

Thanks for the tips all.

Now, off for research...