Originally Posted by
Steelrider81
DT and ST are 29mm, so 3103 seems to be right.
Did you measure the diameters with calipers? French DT and ST O.D. should be 28 mm, and Imperial diameter tubing (English and just about everywhere but France) should have DT and ST O.D. of 28.6 mm.
French chainstay nozzles should be 22 mm, while English should be 22.2 mm.
EDIT - The paint looks pretty thick. I wonder if that's messing up the tube diameter measurements.