Originally Posted by
plonz
That’s a head scratcher. The pic kind of looks like you’re measuring from the center area of the spider. If that’s the case, I’d say move the measurement to the top of the inside chainring.
I did another measurement from the top center of each chainring to seat tube (28.6), and split the difference, and got 47.8mm chainline.
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1989 Schwinn Paramount OS
1980 Mclean/Silk Hope Sport Touring
1983 Bianchi pista
1976 Fuji Feather track
1979 raleigh track
"I've consulted my sources and I'm pretty sure your derailleur does not exist"