Frame Alignment (Bike Pulling To One Side)
 

I have an early 60's Schwinn Traveler 3 speed that I purchased at a yard sale last summer that has some frame issues. It pulled terribly to one side (so much so that when riding straight, the bars/front wheel are noticably turned to the opposite direction of the pull). I've owned some bikes that pulled to one side a bit, enough to prevent you from riding no-handed, but this is the worst that I've seen.

I checked the frame using the old string and ruler technique (looping a string from one of the rear dropouts, around the headtube then back to the opposite dropout, measuring the difference at the seat tube). It was around 1/2" or more off. I aligned the rear triangle to where it's spot-on when measured, and the spacing is correct. I put the bike back together, took it for a spin, and it still pulls to the same side! The front wheel/bars are still noticably turned to one side whent the bike is going straight. It's better, but still bad.

Is there anything else to check? Could the fork be out of alignment? Is there some other way to measure the frame that may uncover where it is mis-aligned at? I hate to not have this bicycle rideable. It is in great condition. Thank you very much in advance for your replies.

The fork blade alignment is the first thing I'd check at this point.

Thanks. How is this done?

By looking to see if it's bent.

There is also a fancy shop tool your LBS has to show the most minor of out-of-trueness. They should be able to tell you.

http://www.parktool.com/images/produ...5727_32064.jpg
Park's FFG-1 is a tool that can help with fork alignment, but will lighten your wallet by around $90.

How much did you pay for the Traveler? That's the most that you can lose on this deal unless you try to fix it.

A spinning wheel will turn in the direction it leans, which is why when you lean into a corner the bike will steer itself around the corner. Also if you roll a coin on a flat surface it will roll in a circle because as the coin falls it turns in that direction.

If your frame and/or fork is twisted, one wheel is always leaning and the bike will steer in that direction. Even if you do the string test, which is primarily to align the rear triangle, the head tube could be out of alignment with the seat tube. In other words the main triangle could be twisted.

Try the string test with the string looped round the top of the head tube or even around the handlebar stem above the headset. Check the distance of the string each side of the seat tube. Then loop the string around the bottom of the head tube and check again. If the head tube is short it may be difficult to spot a slight variation.

More often than not the problem is the front fork. Sometimes in a crash the front wheel will turn at 90 degrees to the frame and the rider will go over the handlebars. The front fork will get pushed sideways as a result.

Stand the bike against a curb and step back some distance from the bike viewing it from the front or the back. Close one eye and look to see if the front and rear wheels are in the same plane.

Unfortunately there is no simple test like the string test to check the alignment of the whole frame and fork. Unless it is obvious to the naked eye, the bike needs to go to someone with the right tools to check it.

I expect a trip to someone with a frame table would cost way more than the bike is worth. Since you just bought it, it certainly doesn't have any sentimental value.

check the wheel dish, see if the rim is centered between the axle ends/dropouts

Many thanks to all who replied to my post. I've several more avenues to explore with this bike. I'll do a few more checks and let the group know the progress. Thanks again.

I just had a steel fork cold set by a local bike builder with the proper tools. One of the dropouts was tweeked, as well as, a misaligned fork and the builder fixed both. A good shop would be able to do the same. It was fast and the bike works well without any hands.

Just an update on my little Traveler difficulties..

I chucked the bike up in my repair stand and looked at it from the front, and sure enough, the front wheel was leaning a bit in comparison to the rear.

I studied it for a bit and done some guesstimation on how far to bend the fork. I removed the wheel and fender, clamped a 4 foot long 2x4 to one fork leg, bent it out a bit, then did the same to the other side to bring the hub spacing to where it needed to be. The 2x4 provided plenty of leverage. This is one of the old forks with the flat, non tubular legs. I was suprised how easily it bent. These forks seem to be pretty strong fore and aft, but laterally seem quite weak. I could see how they could easily be knocked out of alignment.

Anyway, I reassembled the bike and eyeballed it, and things seemed pretty true. Hopped on and took it for a spin and SUCESS!! I took my hands off the bars and could actually ride the bike no-handed. Before I started working on it, this was absolutely impossible. While it still pulls just a smidge, it is very ridable now. I would say the fork may have only been off 3/4" or so, but what a difference that makes!

I really want to thank everyone for their help. You all have helped bring another classic to the road again, and I really appreciate it. I've still got a few more things to do to it, and when it's complete I'll post some pictures.