Hoping there's still activity on this site. I have a 19" 1999 Schwinn Factory BB Red/Silver Frame that I'm starting to build with mostly period parts. (Trying to semi recreate the 1998 Factory XTR that I used to have).
I bought a 31.8 XTR rd-M951 9 speed front derailleur and it won't fit. I also have an old XT FD that is 34.9mm and it won't fit. My calipers show the frame as being 33.1mm diameter at the seat tube. Any help would be apprecialted. I'm stumped as all the info I've I can find says 31.8. I'm starting to wonder if this frame was clear-coated (although I can faintly see and feel a slight depression in the paint where the old derailleur was.
BTW- I'm a huge Homegrown fan and proud to be a member of the site. I'm also a fairly experienced bike mechanic and happy to help where I can.