Originally Posted by
jamesdak
I did get this out for a ride yesterday. Two major issues. First was the FD wouldn't trim or otherwise move after the first time I trimmed it. Had the LBS guys look at it and they said the spring is jacked up despite how low mileage the groupset is. It seems to work most time if you push the shift lever forward a tad as you activate it. But yesterday I finished the ride into a strong headwind with only the 3 small gears in the back available. The seatpost also slipped and I forgot to bring the right size allen wrench to fix that. It came with a 26.8 seatpost and that's what I have on it. But most 531 are larger so I think it's the wrong size post. Going to try a 27 or shim the Thomsen I have on it right now.
I think I remember using a 27.2mm when I had your frame. But it has been awhile and the photos I have are not conclusive. Typically 531C did use 27.2mm, but that really depended on the builder.