I think the switch from 27 to 700c was an early 80's phenomenon in the midwest. The selling point was that you could interchange tubular and clincher tires. Of course this was also the time that narrow clincher rims and light clincher tires were killing off tubulars, so we didn't gain anything except great standardizaion, but it semi obsoleted many old frames.
As far as measuring frames for fit, the only way to tell for sure is to fit a brake and wheel onto the frame. I've done that several times at swap meets where I have one of my own wheels and a long reach caliper handy. You usually check the rear wheel, as this usually has the most drop.
Lacking these implements, you can get a basic idea by measuring from the drop out to the center of the brake bridge. However, a wobbly hand and the distance from the tape to the actual center line of the item being measured makes this less than 100% reliable, especially where the frame was constructed to maximize fender clearance. Measuring my Fuji ( 700c rear wheel with the pads all the way down in the slots of the long reach Gran Compe NGC 500s; the standard touring design) shows a center of drop-out to center of brake-bridge measurement of 14.5 inches or 36.8cm. Any measurement bigger than that will probably require 27 inch rims or super long reach brakes. If it's close, make any deal contingent on actually putting a wheel and bike in the frame, if you intend to use 700c size wheels and standard reach brakes.
Anyone have the numbers for 700c wheel and short reach brake?
Tom Adams, Shrewsbury NJ
>From: "Stratton O. Hammon II"
>Subject: [CR]Change from 27" to 700C?
>Date: Wed, 05 Mar 2003 13:32:02 -0500
>When exactly did the American and English, especially Schwinn and
>Raleigh, quit using 27' rims and switch over to 700Cs?
>Is there any easy way of telling if a bicycle frame, from the '80s, was
>built for a 27" or 700C? I'm thinking here of bikes like '80s Mercians
>or Bob Jacksons?
>Louisivlle, Kentucky, USA
>And please! This is not a chat room. I don't have time to read a dozen
>emails about whether a former member should or shouldn't stay in the
>list--especially when some of the emails are a page long and get
>reposted several times! Keep the personal emails personal. If a member
>is causing problems, take it up with Dale and Ebay.
> > Tom Adams, Shrewsbury NJ Wrote:
> >Just have to hope someone keeps making good 27 inch tires
> > when the three pairs I'm hoarding wear out.