asterisk

What would be the potential result of having a fixed cog on the standard drive side (right side) with a freewheel on the non-standard side (left side), of a fixed wheel. My bottom bracket spindle is the same length on both sides, and I would run the same gearings on each (though this makes me wonder what the result of having different gear ratios within the same drivetrain would be...).

Potentially, wouldn't this act standard-fixed style, with the drive-side cog tightening under standard pedalling while the freewheel would be on its freeside... yet under backpressure and skidding, the freewheel would engage and add stopping power? This is barring any eventually breakage within the freewheel, since they tend to do that.

If you were wondering, this is a posting coming from the same shop that made this bike.

TallRider

So, the idea is that you'd have the back-pedaling, braking-with-the-rear-wheel force distributed over both cogs? I think it'd be adding a lot of weight for little to no gain. Because, the lockring on a track hub is reverse-threaded, so when the cog tries to rotate backwards when the rider resists forward motion of pedals to slow the bike, the cog can't rotate backwards because doing so would only tighten the lockring.

Anyway, I don't see the point of running two freewheels, compared to just running a single fixed cog. Unless you like the clicking sound of freewheels, and the sensation of a slightly loose chain.

sirwilliamjr

I think you could run two different gear ratios on you double freewheel bike, but I don't think that would work on a "fixed-n-free" bike, cause no matter what direction you apply pressure to the pedals, the fixed side is always "fixed" to the cranks. But I'm not completely sure, and you obviously have more experience with dual chainlines than me (very cool bike, by the way!).

-Will

ettsn

Strange, but cool. I had thought of doing something similar on a BMX cruiser. I was thinking of using a flip-flop with a LSD and RSD freewheel (BMX bikes can be left side drive, if you've never seen it) connected up with a L and R driveside crank arm (BMX crank arms can also sometimes be had single as well). Not fixie, but simply double driveline. No good reason other than just the cool factor of a doubled driveline. I also thought it might be cool to find the same exact ratio in a different gearset for one side (44-16 on the right, 33-12 on the left for instance). Curious oddity, but no real practical value.

-Paul

genericbikedude

What if you had two different gear ratios on either side of the bike? Could you skid with the easy side, and ride with the hard side?

asterisk

See, this is the idea here. Would it help add more stopping power? Anything relatlively equivilent to the stopping power added by backpressure onto two cogs instead of one?

Also, the idea is to run fixed on the standard drive side but free on the typical non-drive side.

TallRider

The first part of my reply was talking about a fixed+freewheel combo, the second part about two freewheels. Sorry to be confusing.

I don't think a fixed+freewheel would add more stopping power, unless your fix cog tends to loosen. But, if it's done correctly, with a track lockring, that won't happen.

UCSDbikeAnarchy

From a practical point of view I think that the minimal addition stoping power proably doesn't warrent the added complexity. But looking at your other dual-drive, I say who cares about the complexity, just builld it for the pure fun of it. Obviously you like to play with your tools.

TallRider

I don't think there's any added stopping power to the setup.
-
Yeah, totally. It looks pretty cool.

wethepeople

I _WANT_ that bike.

I have often thought about building on kinda like it.

genericbikedude

Hey Spencer--I think I used to know you back in Santa Cruz--I'm Drew, and I lived in the Barn and worked at Slug Books. Good to see you building such hot bikes at the coop!

Anyway, heres what I always wanted to try, similar to what the OP did:

--Similar setup with two drivetrains, both with freewheels
--Right (forward) side has steep ratio, say 52x15 or something.
--Left (backward) freewheel has easy ratio, say 43x22
----Something with a lot of skid patches


The left side would freewheel when the bike is moving, and the right side would freewheel when skidding. Super-easy skids on the left, and a hefty gear for going fast on the right. Wouldn't help anybody to get up hills, but it would be *somewhat* more reasonable than a normal brakeless fixie. I'm surprised that SB hasn't tried this yet.