From Claude Genzling's book (all measurements in mm, center-to-center):
F. Coppi's bike exhibited in 1977:
Seat tube: 582 Top tube: 565 Seat angle: 72.2 Head angle: 72 Fork offset: 50 Trail: 58 Front center: 600 Chainstays: 432
Note that the trail figure given would require a wheel diameter of 707 mm - way larger than even a Clement Del Mundo sew-up (which measures 30 mm in width and 690 mm in diameter)
F. Coppi's bike from an old photo:
Seat tube: 570 Top tube: 570 Seat angle: 72.6 Head angle: 73 Fork offset: 50 Trail: 52 Front center: 600 Chainstays: 440
_IF_ these are correct, they indicate more "modern" geometries than those on Chuck's bikes. (The photos of Coppi's bikes clearly show less fork offset than many contemporary machines, so even if the measurements aren't 100%, they indicate a trend.)
Finally, here is one I have measured:
Learco Guerra, ca. 1950s, Campagnolog Cambio Corsa:
Seat tube: 586 Top tube: 572 Seat angle: 71.5 Head angle: 72.5 Top tube: level Fork offset: 57 Trail: 49 Front center: 603 Chainstays: 420-450 (adjustable) Wheelbase: 1010-1040 BB drop: 77 Wheel diameter (Del Mundo 30 mm sew-ups): 690
When I measured the trail, it was closer to 40 mm, so it is possible that the fork offset is more than the 57 mm measured. Overall, I have reasonable confidence in the measurements above, +/- 5 mm and 0.5 degrees. (Measuring trail is almost impossible, as you are projecting the head tube way out, and half a degree off will result in great changes down there!)
For an upcoming article in Vintage Bicycle Quarterly, with a friend,
we measured more than a dozen old machines. Some interesting facts
appeared - some of the old bikes have very little trail (like Chuck's
measurements indicated as well), yet handle very stably. Working on a
hypothesis that explains why... all in the next VBQ.
--
Jan Heine, Seattle
Editor/Publisher
Vintage Bicycle Quarterly
c/o Il Vecchio Bicycles
140 Lakeside Ave, Ste. C
Seattle WA 98122
http://www.mindspring.com/