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[Tack]

de5sme7 is behind...


That is hardcore, though I have cycled with only one pedal. Hard to start going though.

[zchris13]

which leg was missing left or right?

left = no gear changing

right = no rear brake

i expect the right

How does this work out?

[Aqizzar]

which leg was missing left or right?

left = no gear changing

right = no rear brake

i expect the right

I could also have been a one-speed bike with two handbrakes, like any non-serious bicyclist's bike.

[Jude]

which leg was missing left or right?

left = no gear changing

right = no rear brake

It was the right but I have no idea what kind of bike would require legs to change gears and there's such a thing as handbrakes

[Ashmore]

There's a guy here in town who rides a bike even though he appears to be paraplegic. Not sure what kind of modifications he has on that Japanese racer. Besides the wheelchair mount, that is...

[Puck]

There are quite some one legged bicycle riders. IIRC pedaling is less of a problem than keeping balance in tricky situations. (at least when it comes to mountainbiking.)

Friend of mine has a bike shop... and he just build a special full suspension bike for a guy with ONE ARM. Weird contraption to strap the left shoulder in, and a hydraulic disc brake set that comes with a predetermined break force distribution between the front and rear brake.

Funky thing...

Oh, and even more interesting, from technical point of view....
One of his customers has problems with their knees. Pedaling in one direction for longer periods of time hurts for them. So they modified some weird chain routing idea from the 18th century or summat... and now he can pedal in BOTH directions, always going forward. And the freewheel behaviour is mainained.

[Duke 2.0]

Oh, and even more interesting, from technical point of view....
One of his customers has problems with their knees. Pedaling in one direction for longer periods of time hurts for them. So they modified some weird chain routing idea from the 18th century or summat... and now he can pedal in BOTH directions, always going forward. And the freewheel behaviour is mainained.

Wait, what? How can you pedal both ways and maintain a freewheel behavior? That sounds like one magic bike.

[Puck]

Fixed rear hub with 2 freewheel sprockets, even pulling in the same direction, combined with some funky chain routing.

Zero custom parts, just the sprockets are modified a wee bit so they can take 9-speed chains, because the chain has to be bent a bit, just like when using a derailleur. And you dont get sprockets with an integrated freewheel that can take 9-speed chains.

Lemme see if I can dig up some pictures.

One you understand how it works, its really really simple.

[zchris13]

Still sounds like magic.

[Puck]

Isnt there an old saying ... somethign like... sufficiently developed technology is not discernable from magic (and the other way round) or something?

Either way. The idea is 200 years old and really really simple. Once you get it. I didnt believe it til I tested it, either.

I didnt find pictures, Ill call him sometime the next days and will ask him. I know he has them (same with the one-arm-guy-fully), I just dont know where to find them online.

Simplest explanation with words would probably be:
the chain is routed in a way so it pulls from the front on ONE sprocket and makes the OTHER one freewheel (at double speed, obviously) if you pedal normally. If you pedal backwards, its just the jobs of the sprockets are reversed. ie, the one that was driving before is now freewheeling. If you dont pedal , both spin freely.

Damnit, without describing the way the chain takes, its useless to put it in words

edit: just found an US patent, that does the same trick about a dozen times as complicated. I'll keep looking

edit 2: there it is:
http://www.patentstorm.us/patents/6695332/description.html too bad the bigger version of that picture is only vierwable by registered users. But thats basically the same thing as the one my friend came up with, if I see that correctly. The stuff described in that text is a bit funny. The problems they mention can probably not solved by this kind of drivetrain. It just helps keeping the stress on the body down, which is important for that particular customer of my friend (the guy had an accident and his knees start to hurt quickly). I would NOT want to use it to ride my bike uphill "more safely". Seriously.

edit3: DAMNIT. Still not the same design. Still uselessly complicated with that "auxiliary chain". But were getting there.

[Duke 2.0]

 I think I see what you are getting at there. Text isn't exactly the best medium to share technical designs over. But basically you can pedal forwards, you can pedal backwards, and not moving the pedals makes it freewheel.

[Puck]

Aye. Personally I would hate it to death, since I'm pretty good at the trackstand, in fact so good it became an integral part of biking for me. I hate to put my feet on the ground unless I'm done riding.

But I'm not so good i can do it without any pedal movement.  So this bike would take me right into the traffic when I'd try to stop at a red light (not that I do that very often, but sometimes you just HAVE to)

edit: and NOW I remember what was really really weird about that drivetrain: you cannot, never ever, roll backwards. Makes a REALLY nasty sound, too, if you try to I dont wanna think that patent I posted above through, but maybe that one can do it. Id say, from a quick guess, thats something you cant build.

[de5me7]

which leg was missing left or right?

left = no gear changing

right = no rear brake

i miss read an earlier post. i was refering to a motorbike

one most modern motorbikes you use ur left foot to change gear and your right to break (rear brake).
It was the right but I have no idea what kind of bike would require legs to change gears and there's such a thing as handbrakes