It makes sense to have shorter top tubes on older frames. If you fit a bike so that you have a "fistful" of seatpost showing, as was common back then, you can't ride a "square" frame, as the top tube length for a given rider can't change too much.
Jan Heine, Seattle,
whom they'd put on a "compact" 54 cm frame today and would have put
on a 63 cm frame in 1948, but all with 56-58 cm top tubes!
>Correct me if I'm wrong, but I think this was "standard" geometry for
>bikes of this era. I have a 1971 63cm Mercian with a 58cm TT that I
>have been fretting over for a little while now (I'm 6'5" with longish
>arms). From my research into this frame, a short TT was common.
>Date: Wed, 29 Dec 2004 10:51:27 -0500
>From: "Steven Willis" <email@example.com>
>To: <firstname.lastname@example.org>, <email@example.com>
>Subject: RE: [CR]re: ebay outing: gios super record..sad
>Can I start this off in another direction? Why would any builder make a
>62cm frame with such a short 57.5 top tube. Is it me or should it be
>longer. Hell with my legs and arms I could ride this frame but they do
>not make a stem long enough for me, not that I would want to ride a stem
>that long. Steven
>The Bike Stand
>1778 East Second Street
>Scotch Plains NJ 07076
>-- Jason Moore