Nashbar flip flop hub
 

I've just scored a 70's road bike with semi-horizontal dropouts and would like to try building myself a fixed-gear bike. Nashbar sells a flip flop hub for $50 (here), which is the cheapest I've seen. Anybody used it?

wow, i've never seen those. looks nice, anyway.

There's little information out there about Nashbar track hubs

However, you can pick up a set of IRO HUBS for $69 or a rear hub only for $40. These get excellent reviews around here.
Also, bensbike on ebay sells the same hubs, except in black for $50 a set.

I believe you will run into a spacing issue with the naashbar hubs. They only come in 120 mm spacing and are not adjustable. Your frame is either 126 or 130mm. I agree with the above mentioned IRO's. They come in multiple spacings and are quite durable. They will be my next set of hubs. The one thing I like about the nashbar hubs is the dual track threading. I wish IRO had that option.

Thanks for the tip on IRO! Can somebody explain to me what dual track threading is? My understanding is I would need a track cog and lockring, that can thread directly onto the hub body, as well as a one-speed freewheel for the other side...

Track threading has counter rotating threading for a lockring. The nashbar hub has this on both sides so you can run two different track cogs. The IRO and other hubs have the track threading one side and standard threads on the other for a freewheel. These are known as flip/flop hubs.

You should be able to replace the axle for about $10-15.

well, you don't really need a freewheel... but all that aside, dual track threading means the hub is threaded for a cog and lockring on both sides. more versatile than a regular flipflop hub, since you can run a freewheel on one side, or you can go double fixed.

Is fixed/fixed really worth it for a road conversion. Esp w/ semi horizontal drop outs. I mean to make it worth it it seems to me that you would want a 15 and 18 tooth cog on the back for example. Like a 15 / 16 or 17 would be not worth the effort in flipping. So will there be enough room with drop outs instead of track ends?

Actually a 15/17 may very well be worth it. That's like a 12% decrease in gearing, like going from a 76" to a 67" gear, pretty significant. I know my main ride (47/16) is 77" and my rain bike (42/16) is 69" and the difference is huge.

Oh, and depending on the axle, you may not need to replace it. You will, in either case, need to get some spacers to slap on there. That's very common. Everyone's favorite Suzue Jr. only comes in 120mm spacing, for example.

From IRO's web site they say that the hubs are not easily adjusted for spacing. My guess is that nashbars's hubs are made by the same people as IRO's. I have a suzue basic and it was easy to respace.

I respaced my bensbike hubs to 126mm (they're the same as the IRO's. both made my formula) and the axle is a little bit short.

This is a valid concern becuase chain length will be an issue, especially with semi horizontal drop outs.
It will either be too short or too long, depneding on which you cut it for.

Unless the axle's completely non-standard or can't be removed, any hub can be respaced. Period. I'd like to know why IRO says theirs can't.

As for the chain, not so much. Case in point, I went from a 16t to a 20t freewheel on my mtb just the other night without lengthening the chain. I could probably even move to a 22t freewheel without difficulty. This is on a Bridgestone frame with fairly typical horizontal dropouts.

I just researched a bit to find out where I got the info on the IRO's. It appears I miss read Sheldon's site. The axels are long enough to fit 130's and can be respaced. Here is his description.

These are really nice! Double-sided fixed/free rear hub in 120 spacing, with standard track 42 mm chainline to fit most track frames and many road bike conversions.
Designed with a look remeniscent of the classic Campagnolo Nuovo Record, with milled flanges with lightening holes.

These hub sets have solid axles with good track nuts, large serrated locknuts to keep them from slipping.

Sealed cartridge bearings, 32 holes only. Does not include lock ring for fixed gear cogs (but if you leave the lockrings off, you can install singlespeed freewheels on one or both sides.)

Axles are not readily changeable, so these really can't be converted to quick release.

The axles are, however, long enough to add spacers for frames up to 130 mm spacing. Front: 275 g, Rear 330 g.

I have the Nashbar Flip-Flop Hub on the rear.
Also running the matching front hub.

Several hundred miles so far, and they could not be better.
Smooth. Strong. Attractive. Built up fine. Rear comes with two lockrings.....

:)

I've got the IRO hubs and they looks like they can be respaced to me. I haven't done it, but they don't look weird in any way.

BTW - I've been very happy with my IRO hubs. No problems in the building of the wheel. Nice fit a finish. Bearings seem tight and smooth. Great experience overall with them.

ditto. Sheldon claims that they are re-space-able to 130, but I dont see how..

I measured my dropouts and they're about 1" long horizontally. Am I correct that that would give me a range of about 3-4 teeth in terms of using two different cog sizes?

I believe each section of chain is 1/2 inch, That would give you room for up to a 2 tooth difference. But of course this is an assumption.

Okay, I was thinking if I could move the wheel back 1 inch, that'd give me room for two extra links above and two below.

If the frame is steel you can squeeze it a few mm or spread if a few mm with no problem.

Re the Nashbar hub, unless you are just bent on building your own wheel your LBS can order you a pre built wheel from QBP for about $100 on a Suzue flip flop, Mavic MA3 rim and DT spokes.
FWIW,
Raymond

The IRO Hubs can be respaced because the axles are 180mm.

All the Best,
Tony

Dang quick reply option - anyway, see below, thanks. :beer: on me.

Tom

If you want to run a bigger difference between rear cogs on a flip/flop hub, you can carry a few extra chain links and an extra master link in a seat bag (The SRAM chains and master links are a good option). That way you can keep the correct chain tension and have whatever gearing you need to get you up a hill or down a hill.

Tom