Reminder: many Colnago rider's geometries are here:
http://www.colnagonews.com/
Angel Garcia
Long Valley, NJ
> 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/