Joined: May 2015
Posts: 11
Likes: 3
From: East Coast
Bikes: I have owned Carlton Franco Suisse, Schwinn 62 Paramount, Colnago Super, Rigi, Bianchi Super Leggera, Pake, San Rensho Export, Frejus 62, Raleigh Gran Sport 62, and many I have forgotten.
Front is 47-50, but the 28 tooth rear freewheel is about all the Gran Sport can handle. I had to leave a little slack in the chain. Even with a frame indent, the 47 chainring runs a few millimeters from the frame.
The dropouts have soft rounded edges as though cast, but are not precision.
As for what is "stock" on these bikes -- I remember in 1962 a dealer friend ordered two dozen Legnanos from Avenia and was able to spec them, component-wise.