Don't forget that geometry and design varied over time. For me, the older the bike, the larger the frame size I need.
According to modern formulae I need a 51.5cm c-c modern bike. I add 1-2 cms for 1980s, 2-3 cms for 1970s, 3-4 cms for 1960s, 4 cms for 1940s-1950s.
If I bought a 51.5cm bike from the 1950s it would be WAY too small to be comfortable. I made that mistake with a 1960 Atala, 1968 Paramount, 1972 Atala, and 1973 Legnano.
Aldo Ross Middletown, Ohio, USA
----- Original Message Follows -----
From: Ken Freeman <kenfreeman096@gmail.com>
To: <classicrendezvous@bikelist.org>
Subject: Re: [CR] vintage frame size question
Date: Fri, 20 Mar 2009 18:15:12 -0400
> You need to know your cycling inseam, not your trouser
> inside-leg. This number gets multiplied by 2/3, to get
> your frame size. My inseam is 81.8 centimeters (32.2
> inches). Multiplying, the frame size is 54.5 centimeters
> (21.5 inches). This length is compared to the seat tube
> length center to center. That's the basic frame sizing
> approach. This approach generates a size that is at the
> large end for me, but that's probably more correct for a
> vintage bike.
>
> The other attributes of bike and frame fitting are still
> significant, but they are still secondary to saddle
> height.
>
> Ken Freeman
> Ann Arbor, MI USA
>
> On Fri, Mar 20, 2009 at 3:06 PM, James Doolittle <
> JDoolittle@bentwaterclub.com> wrote:
>
> > I am a rider, not a collector or mechanic. I was fit in
> > my mid twenties by a man who was in his 70's at the time
> > , Ceasar Moretti Jr. He was a six day racer in the
> > 1930's thru the 1950's. This was over 30 years ago. He
> got it right. I'm 57 years young now and that frame size
> > is still what fits the best. Over the years I've always
> > had at the minimum two bikes and as many as seven at one
> > time. Almost all within the CR timeline. Like many on
> > the list, I've crashed, had stolen, been given by teams,
> > bought as junk or from the most reputable shop many,
> many bikes over the years. I've experimented with sizes
> > as much as 3 centimeters one way or the other and always
> > sold those bikes. A couple were very impressive bikes
> > that anyone in their right mind might have kept, but
> > they never felt right. The key is to stick with your
> best fit. Happy riding! >
> > James Doolittle
> > Spring, Texas - where the dogwoods and redbuds are
> > blooming in the forest!, Texas
> >
> >
> > -----Original Message-----
> > From: classicrendezvous-bounces@bikelist.org
> > [mailto:classicrendezvous-bounces@bikelist.org] On
> > Behalf Of Robert Goughary
> > Sent: Friday, March 20, 2009 12:34 PM
> > To: classicrendezvous@bikelist.org
> > Subject: [CR] vintage frame size question
> >
> >
> >
> > This is a good one for all you with more experience than
> > me - particularly those of you that have built frames or
> > sized people up in shops, etc...
> >
> > when buying a vintage frame sight-unseen, how do you
> > know if the frame will fit? Not - what would be the
> > perfect fit - but let's say you run across a Richard
> > Sachs from the seventies and the only thing you know is
> seatpost height - what do you do? >
> > I am 5'11" or so - normal build and size - how do i know
> > what are the fitting extremes? - what is to small, way
> > too small and too big and way too big? Example - can a
> > 6' guy fit on a 54" frame? Or a 60cm? (seatpost C-C)
> >
> > I have a couple bikes that fit - so i'm more concerned
> > about the random find online or maybe at a flea market,
> etc... >
> >
> > Thanks
> >
> > Rob Goughary
> > Stamford, CT USA
> >
> >
> >
> >
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> >
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> >
>
>
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