Originally Posted by
unterhausen
that makes no sense. And untold thousands of steel frames have been aligned using this same method. Bend one at a time, measure. Tweak until you get that side right. Bend the other one. By pulling them apart, you have no idea.
Of course, it does require the ability to measure, but this is the framebuilding forum, you can't make something if you can't measure it.
Believe it or not, it is not difficult to bend as I described and then measure both width and center. Every shop I've ever worked for had a frame alignment gauge. Someone doing it has home can use a string.
When someone on a forum asks about doing something, I'm going to assume I'm not addressing either a shop mechanic or a frame builder, but someone doing it for themselves without a frame alignment table. So when I picture the kind of ham-fisted mistakes levers and clamps can do, I recommend a method which generally works very well because it is self aligning and doesn't involve putting levers on paint and thin tubing.
So what is it that doesn't make sense, exactly?