My bike had a slight tendency to pull to the right while riding. I assumed my frame or fork was misaligned because I made it without any professional jigs. To make things accurate I used straight edges, a right angle square, perfectly dished wheels, strings and whatnot. I was confident the frame and fork were aligned to within less than a millimeter. At any rate, while riding there was always a slight feeling that the bike pulled to the right. It was a nagging feeling that never went away. So after a year of riding it, I examined the fork and frame again with the utmost care that my rudimentary system would allow. I found a half millimeter issue with the fork which I fixed (blades were positioned to the left ever so slightly). There was a tiny error in the stays so I moved them too. Headtube and seattube were eyeballed perfectly parallel as far as I could tell. Wheels were centered and parallel. Still, the issue would not go away. The bike kept on pulling to the right ever so slightly.



Somehow (maybe in a dream), the idea that maybe the issue was located in the seat occurred to me. It was an old leather Brooks B17 that I had used for a decade and then put into a box for another decade. It was well used but not worn out. There had been an inch of tightening at the nose. It was kind of lumpy, perhaps distorted from a decade of storage in an unheated garage, but it was comfortable enough.



So I removed the Brooks and installed an Avocet plastic saddle. Now the bike glided perfectly! I was on cloud nine. For the first time I really enjoyed riding the bike. It tracks like an arrow and handles so well. I assume the old Brooks saddle positioned my pelvis in a way that caused the sensation of a misaligned frame.



There is a story I heard of a skin-on-frame kayak builder who replaced the skin of a customers boat who felt that the boat pulled to one side. The builder wanted to make the customer happy, but actually did not think changing the skin would make any difference in how the boat tracked. There were no errors in the boat alignment, and after some test paddling the builder felt the boat tracked perfectly. I don’t know how that story turned out, but it makes me wonder just how complex these issues are. While the professional framebuilder will turn out a perfectly aligned frame, the random misalignments of the other components, or our bodies themselves, can remain.