frame alignment confusion
 

Perhaps I should be posting this in the framebuilders subforum, but I opted for greater traffic.

I've run into a snag with the Ted Williams I'm working on. I checked the alignment using Sheldon's string method, and after minor adjustment the chainstays are aligned. However, when I put the rear wheel in and center the rim between the chainstays, it's off-center vis-a-vis the seatstays. I thought maybe the wheel wasn't dished properly, but if I mount the wheel backwards, I get the same measurement. It's about 21mm from the rim to the seatstay on the non-drive side; 26mm on the drive side.

I haven't yet done anything with the dropouts (I don't own the tool) but they appear to be reasonably straight. Is it possible for misaligned dropouts to throw the wheel off in that way? Or do I just have a funky frame? Any alternative theories, or ways to check various alignment issues without a frame table?

The string method can be inaccurate and give misleading results if the string isn't very tight and the measurements taken with great attention to detail. Could it be that you adjusted your frame out of alignment?

Several prerequisites:

Is the wheel true and dished? Check for true on a bike frame with brakes and check for dish with a dish guage.

Does your frame have horizontal or vertical dropouts? If horizontal, does it have adjuster screws? Are they adjusted so the plane of the wheel is at least parallel to the plane of the main triangle? The ends of the rear axle need to be equidistant from the BB axis, for the wheel to spin in or at least parallel to the plane of the main triangle.

It does have adjuster screws, and as Road fan said, make sure they are even.

When in doubt, assuming you don't have a micrometer, back them all the way out, then screw them back in, equal turns on each side..

If the wheel fits the same way when reversed its gotta be the frame.

There is a tool to make the dropouts square to each other, a tool to align the dropout hanger, and a guide to lay on the side of the frame to check rear triangle vs the head/seat tube (which is what the string is doing). All worth having; maybe run the frame to a good bike shop, they should have the tools or an alignment table.

If you have someone to help, or have some clamps, run a rigid rod or straight edge from head tube to seat tube inside the dropouts and measure from that.

I'm confused also...
 

When you reverse the wheel do you still get the same measurement value from the same stay? If so then your wheel is not properly dished - it is centered on the hub rather than offset to account for the freewheel.

If, however, the measurement changes then it is probably not a wheel issue.

http://www.bikeforums.net/attachment...1&d=1256667653

Run the string up and around the head tube and ensure that it is very tight. Use a thing and strong string not a piece of binder twine. You want to be as accurate when measuring the distance from the spring to the side of the seat tube.

http://www.bikeforums.net/attachment...1&d=1256667723

Also, measure the distance between the inside faces of your rear drops. The measurement should be 120mm or 125mm if you are running an older frame set. If the measurement is not either or those, then you do have a chain stays alignment issue to deal with.

I have written a complete article on how to preform this simple frame test and then implement repair. If you send me a personal email, I will send you the link and access information to the article.

Hope this has been a help.

This doesn't make sense to me. Shouldn't the rim be centered on the over-locknut width? If so, flipping the wheel shouldn't change the rim-stay distances.

When I run the string exactly as you show in the previous post, the string-seat tube measurement is identical on both sides. However, if I tie the string off at the brake bridge, it's off by almost 2mm. So it looks like I have a sloppy frame.

I'll talk with the local shop and see what they'd charge me to scope it out on the table and see if adjustments can be made. This isn't a bike I want to sink a bunch of money into. If that course is cost-prohibitive, I'll fudge it the best I can.

You're right...
 

You are correct. The measurement should be the same either way when the wheel is reversed. Not sure what was going on in my mind at the time.

Any chance that you took some pictures to help demonstrate the problem. I am kinda interested in how this repair plays out. I do wish you good luck.

Could it be the the driveside dropout is a tiny bit higher than the non drive. And a tiny bit higher at the dropout could manifest itself to be a few MM up where the rim is?

Just a guess...

And its a good guess.

Aside from it being a 'Ted Williams' what kind of rame are we dealing with?

I think this is what's going on, and my plan is to file a smidge off the top of the non-drive side dropout. As you point out, it won't take much, and I don't think it will compromise the integrity. At least not enough to matter for the way I ride.

[Aside from it being a 'Ted Williams' what kind of rame are we dealing with?]

This is one of the 531 Ted Williams bikes made for Sears by Puch. It's been an interesting ride and I haven't been on the bike yet.

Something to consider is the axle diameter. If its smaller than the dropout width there's a possibilty the wheels rocking to one side.

This is a good point. Using a large crescent wrench to gently bend the dropouts so as to tilt the wheel properly in the vertical direction could shift the axle's position high of one side and low on the other side (if there's slop in the dropout slots, or if you file to get some slop). If you tilt the axle in the dropouts, you need to tilt the dropouts or the wheel will just clamp down in the wrong place.

That's a helpful observation. This is going to be a bit tricky - getting the wheel in the right place and keeping the dropouts parallel.