Originally Posted by Doug Fattic

A natural question for a bike enthusiast to ask is how important is frame alignment and/or what difference does it make? Of course this kind of discussion falls more into the area of attitude and opinion instead of empirical evidence. What I can say is that some modern day shifting problems are related to rear derailleur misalignment. And some knee issues can be traced back to a leaning seat tube that results in pedal platforms being twisted. But how does alignment effect performance and handling is a difficult question to answer because the evidence is antidotal.

I can also tell you from years of reconditioning frames that many frames are out of alignment and it is not uncommon for them to be badly out of alignment. During the classic era in Europe, some builders had really modest equipment and were required to make them quickly in order to make any money. I can also say that I have ridden many of those bikes before and after I have worked on them. I have also asked some of my customers if they could tell any difference. And of course the results are mixed. Not surprisingly sometimes they would say they could tell a real difference and sometimes they couldn’t.

I believe it does make some difference but not a dramatic difference.For me it is not an important question because I have always had the right tools and whether repainting a frame or making a new one, I can get it right.By the way there is no such thing as perfect alignment because tubes all have issues of some kind.It is normal for them to be curved 1/16” or more.Most production frames were considered within tolerance if they were out less than 3mms.Most custom build hold to a standard of less than 1 mm.