Pedal forward in one gear. If you pedal backwards, you still go forward, but in a different gear.

Too cool for words, or just plain bizarre?

Pffff. I'd hit no-hands and brakeless...

Yeah, that's really crazy. You do have to remain pedaling though, right? Makes me wonder how difficult it is to get used to the transition from going forward to going backward. And I guess that you have to run brakes also, right?

id rather have a sturmey TF



someday ill find one.

i dont get it. how do u stop? back pressure would put u in 2nd gear, right?

It coasts.

how is this fixed gear? isn't the whole principle that one gear coasts while the other is in use?

Yes, you need brakes. And the bike won't roll backward. Trackstanding could be a bit more difficult.

They are ss, not fg. Hirondelle, a French company, produced bikes like this from '24 to '40.



https://en.wikipedia.org/wiki/Retro-Direct

https://users.skynet.be/ppc/retrodirect_drive/

they're obviously not single speed...

Well, from reading my email these past few days it seems you're close

So if its not fixed...and its not single speed...whats it doin in this forum? (c'mon, someone had to say it)

heh. i got the ASC, but the TF still proves elusive!

This really makes me appreciate my Fichtel&Sachs Torpedo Duomatic 2 speed Hub with coaster brake.

i don't like the complicated looks.... i like fixie because it has the most simple gear stuff...

I've been thinking about trying to do one out of an old frame for awhile, just for the goofiness of it all, but it seems like one would be getting oneself into some welding and/or metal fabrication to make the little hangy downy thing with the pulley wheel on it.

If only you could run a Sturmey 3-speed like that...

Yes they're superb hubs aren't they

Yes... as said above, these are not fixed gear. The only way this can work is one freewheels while the other drives the wheel. when you pedal backwards the freewheels switch jobs. You can still coast... however for some reason you cannot roll the bike backwards... both of the freewheels lock up.
we've built a few of them at the local Co-op, the are a ton of fun and freak people out.

i don't care if this is not fg or ss related. i thought it was an interesting idea. thanks for posting.

what kind of difference in gearing can these things handle
?

Coolest.

It seems to me that there are two freewheels: an outer, smaller and a larger, inner, on the hub.
So when you pedal forward, the pawls of the outer freewheel engage and the gear ratio is determined by the outer freewheel and the chainring. The inner freewheel is freewheeling, functioning as a simple pulley for the chain.
If you pedal backwards, however, the outer freewheel is not opposing the movement of the chain, and it's the lower run of the chain that engages the larger, inner freewheel, moving the wheel clockwise. Now it's the outer freewheel that works as a pulley.

I believe this bike can coast.

So what you have here is a double singlespeed, that achieves gear change without deraileurs or planetary gears.
Very smart idea. I like.
Extremely long chain: I don't like.

EDIT: I revised my story several times.

By the way:
The pulley (the hangy downy thingy) is by far not the biggest technical challenge here. You have to be able to fit two separate freewheels on the hub.

cheesus, why do you guys get so technical?

now I gotta go get a park HDT-5 hangy downy thing tool.

dammit

that things like looking at an Escher drawing

I like, has anybody ever ridden one? How hard is it to get used to pedaling backwards?

They can handle any gear ratio switch that you can handle. We also used a BB cup to thread onto half of the threads on the inner freewheel, which holds the outer freewheel on. Its a very sturdy design.

That black peugeot posted above was made by me and a few others at the local coop.