Bicycle Mechanics - Cold Set Frustrations

I "cold set" an old road frame using the 2x4 method. I went from 126 spacing down to 110 to fit a 3 speed hub. Now I am finding that the wheel is not centered properly when using the rear brake bolt as a reference. In the pics the wheel is properly centered between the chainstays, but clearly not between the seat stays. How should I remedy this problem? What steps do I need to take to measure and correct?

http://www.miniband.com/bikeforums/cs1.jpg http://www.miniband.com/bikeforums/cs2.jpg http://www.miniband.com/bikeforums/cs3.jpg

The quick and dirty method is to use a wheel with a solid axle and track nuts, and then just move it around in the dropouts until it looks centered and then tighten down the nuts. That's what I do on my 2x4 spread, horribly un-aligned commuter. I don't know if this will work for a road bike though. Mine is a mountain bike with a beefy "pathway" tire that probably eats up any eccentricities (at least I can't feel any pull). You might try it with a QR skewer or a track nut skewer in a hollow axle, but I would not recommend either (actually it's a very bad idea to use QR skewers if the dropouts aren't aligned parallel to each other because the QR may not be pressing everything together all the way even though it feels tight). As for measuring things, did you get the 2x4 idea from Sheldon Brown's article (http://www.sheldonbrown.com/frame-spacing.html)? If you haven't seen it yet, it goes through a cheap method of using strings to check stay alignment.

Yes, I got the frame spacing info from Sheldon Brown's site. I am thinking that this might be a symptom of misaligned dropouts more than anything. They LOOK straight enough, but that just might not be good enough...

The wheel i'm using has a solid axle - the hub is a Shimano 3 speed. By "move around" do you mean to use the wheel to bend the frame into place? Like use the rim to get torque to force the wheel into alignment?

I mean "to force the wheel into alignment in relation to the rear triangle"

And I guess a 3 speed axle isn't really solid either...

With that kind of reduction in spacing, that will definitely jack up your dropout alignment. I have a frame in a similar way and have found it's best to thumb tighten one side, get the other about where I want it, thumb tighten that and then go back to the first side to wrench it down and finally back to the second and do likewise.

It's a bit slower but otherwise you end up tightening the nut down on just one dropout which will align your wheel with one misaligned forkend and then there's really no hope for getting it straight.

Re-dish the wheel.

Thanks for the suggestions. Going back and forth on the axle nut tightening is a good plan. I re-bent the frame a little bit, and eyeballed the dropout alignment trying to straighten with a wrench. The result? It's pretty close. I'll re-dish the wheel today.

Took the bike out for a test ride, and it's pretty awesome. It's just what I was going for, and I couldn't feel the 1-2mm that the wheel is not in line with the frame. I'd say it's great for a 12 speed pulled from the trash. I think I love this bike.

Does anyone know of other road bike / 3 speed conversions? Maybe w/ pics?

I'll re-dish the wheel today.

From what I've learned on here, before redishing, the wheel should be slid in backwards to see if it falls in the same relative place or not. If it does, than the wheel doesn't need redishing, but possibly a little more work on the frame.

Ideally, the frame should be adjusted so that it's perfectly aligned. If he doesn't have the tools/equipment to do so, or doesn't want to pay a shop to do it correctly, redishing the wheel will get it aligned to the frame.

You can check the alignment of the rear triangle by looping a piece of string to the head tube, and then pulling taut and tying each end to the rear dropouts. Now just measure the distance from the string to the seat tube on each side, should be the same! If not, you know what to do. :D

Aligning the dropouts themselves I like to do with an old front hub. Bolt the hub to one dropout, and then use the hub as a 'handle' to bend the dropout until it seems like its aiming at the other one. Go back and forth until they both point at each other, and both rear triangles are aligned.

I'm always a bit amused at how often we use the term 'cold set', which is just a very pretty sounding euphemism for 'bent'. I guess no one wants to hear their mechanic say, "Well, I just finished bending your frame." ;)

peace,
sam

By "move around" do you mean to use the wheel to bend the frame into place? Like use the rim to get torque to force the wheel into alignment?

What bostontrevor said. Also it's a lot easier to do that while the bike is upside-down, but that makes the alignment a little harder to eyeball. Glad to hear the bike is working out for you - the best bike is the one you didn't pay for. :D Since you can't feel any pull anymore I wouldn't worry about getting the alignment perfect - the important thing is the wheel is in line with where you're trying to go. The axle should be plenty strong for whatever you're going to do.

I "cold set" an old road frame using the 2x4 method. I went from 126 spacing down to 110 to fit a 3 speed hub. Now I am finding that the wheel is not centered properly when using the rear brake bolt as a reference. In the pics the wheel is properly centered between the chainstays, but clearly not between the seat stays. How should I remedy this problem? What steps do I need to take to measure and correct?

Assuming the string test shows the stays to be symmetrical, I'd guess that the problem is that the wheel is not dished properly. Try installing it backwards, see if it's still off the same amount in the same direction. (This assumes you don't have easy access to a dish stick.)

Some posters have talked about the dropout parallelism, but this wouldn't be related, since the error (only a bit over 1 degree) would be the same on both sides. Parallelism isn't as much of an issue with thin stamped dropouts such as this frame has as it would be with thick forged or cast dropouts.

Sheldon "http://sheldonbrown.com/frame-spacing" Brown
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