John Betmanis wrote:
>
> Sutherland's 3rd edition gives the track chainline as 40mm
> for 110m rear spacing and 42.5mm for 120mm. That's off by approx. 1/8"
Campy agreed exactly with Sutherland's (or more realistically, the other way 'round) at least as of Catalog 17 - maybe earlier. I don't know how far back the 40 mm recommendation goes - anyone?
There's a good graphic of this in Catalog 17, on page 52, see it here if
you don't have yours handy:
http://bulgier.net/
Probable reasons for making it 40 mm instead of 38 mm (1-1/2") include the ability to use larger chainrings, and/or not needing such a deep dent in the outside of the right chainstay for c-ring clearance. Also slightly better bracing angle for the right-side spokes on the rear wheel.
Mark Bulgier
Seattle WA USA