Recently bought a 63cm 3.0 frame circa '90 that arrived with 120 spacing.. serial number sez 126 spacing. Can't see any damage.. or toe in of these cantilever rears. Appears the rear hanger has been replaced... has a plate seemingly attaching this new fixture. Possibly this is how the frame was made... ?
I could live with a 120.. I build my own wheels.. .that is doable.. an interesting challenge. I've been high and low regarding opines on how to proceed moving it back to 126... 'just slide a 126 in there and run it'... which can be done with thumb pressure. I can also slide a 130 with "firmer" thumb pressure. One suggestion was a jig.. some type of restriction on the rear triangle to prevent any outward or inward movement of that triangle.. these cantilever rears place the axle around 1.5" behind that triangle intersection. Then a turnbuckle like arrangement to move this spacing out with controlled pressure.. "just enough".
My only reason for considering a chg of this now 120 spacing is the feature of the axle being well behind said triangle intersection. One reads a pile of regurgitated aluminum resetting 'views' on the net.. those pts taken. I was hoping to get some input from knowledgeable frame builders.........
PITA to have to struggle with a sticky rear chging out a tire.. espechially on the road. Guess my prime reason for considering chging it out.