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.

Interesting story. My legs are different lengths, which I didn't find out until I ruined a Brooks. I have always used plastic saddles other than that one. Doesn't put me off center enough to make the bike pull though.

I wondered about a shorter leg too. Bodies are rarely symmetrical or as Albert Eisentraut said during one of his building classes "show me a perfect body and I'll make a perfect frame". The vast majority of my bikes have me slightly leaning my upper body to the left when riding no handed. Both factory and self made. Andy. (whose ride today was nearly perfect...)

Not to be crass, but saddles and bibs don't really fit guys symmetrically. I usually 'hang' to one side of the saddle and my shorts. Normally I never think about it, but when it is 'wrong' I definitely notice and reposition things. I'm positive that this shifts my hips a little bit. My wife even comments that I'm not perfectly symmetric when she is on the back of the tandem.

Mine are exactly the same lengths. I broke one about 25y back (got hit by a car) and they pinned it back together using the good leg as a reference

Coincidentally, our dog is getting a second operation today on her left leg that was broken by a car. The crash happened years ago, but we are just now getting her put back together. Turns out her right front leg was also broken but healed on its own. When they straightened out the left leg, they tried to match the length, but it's not quite right.

I often ride with some stuff in one of my jersey pockets. Maybe my folded-up rain jacket is affecting the handling on my bike ?
How in the world did Greg Lemond manage to even ride a bike - he had only one kidney, so the balance issues must have been immense !

Not buying it that any of this stuff makes much difference except for people telling themselves that it does.

My eyes were never in line with my frames. Got so used to that I rarely noticed - until a PT pointed out my shorter right leg and put me on a 1/2" heel lift. I guessed half that should work out about right as a shim over my cleat and made said shim from 1/4" aluminum plate. Seat up an 1/8". Got on and "OMG! My eyes are right on center." Told my PT. Heard words to the effect of "that's exactly what I would have recommended."

Yes, there is the placebo effect, which is significant in medicine and perhaps in how a bike rides or how the canoe tracks. For me, changing the saddle was huge. I went from a bike that pulled to the right a little to a bike that tracked as straight as an arrow. I don’t understand why, but I found it was an actual fix to my issue and not a placebo. Placebo or not (it is not) I just thought it would be helpful to put my experience out there.
Drew

It was the ghost of the cow haunting the saddle, of course.

"You will moooooove to the right..."

There are some placebos that are safe and effective

I am not a frame builder but if given an opportunity I would like to try it out.
Anyway, I have "corrected' a couple with help from this group and greatly appreciate the responses and feedback.
In January, while looking through Market Place, a Litespeed Catalyst showed up at a very good price, more than half what a complete bike comparably outfitted is being asked on the bay. I know that alignment is key in the build of the frame with no chance of post build alignment with significant investment. This thing was like I had ridden it all my life, hands free on the first ride with impeccable alignment in that position. I reflect @sdodd comment above.
The Montello rear triangle is off by about 2 mm to the drive side. I haven't done anything about it as the rear wheel is dished to compensate. I am now thinking it is past time to overhaul and address the issue along with the finish in a minor way. Besides, the Montello and Catalyst both are 3x9 Racing T with the difference of clinchers vs tubulars (Montello). Might be even a nicer ride though both have Vittoria G+ tires.
What encourages me to do so is the alignment I did to another frame that was a bit more out of alignment without any consequences.

Bottom line is this thread discussion of ride quality was inspiring, thanks!

Maybe something to do with how the camber of the road interacts with the steering geometry?

Does it do the same on the crown of the road? and does it go left on the left side of the road?

"Maybe something to do with how the camber of the road interacts with the steering geometry?"

maybe...This is why US market adult trikes have their driven wheel on the RH side, to help mitigate the roads crowning. Andy