Listers,
This sizing discussion reminds me of my own sizing pilgrimage.
In late 1971 my considerably-upgraded 21"/53 CM Peugeot UO-8 (Brooks Pro saddle, Suntour all-alloy derailleur, etc.) had just been stolen from our co-op housing's front porch and, being a full-blown bike addict by this time, I spent tuition money to replace it with a Peugeot PX-10, my first all-531 bike.
Because the prevailing wisdom and popular books dictated that touring frames should be taller, I insisted on a 23" PX-10. (I was 5'7" tall, and my pants inseam was (and is) 26.5 - 27". The guys at Collins' Cycle tried to dissuade me but I was in college and knew everything....)
That 23" PX was a fine bike but far too tall and awkward for me, not to mention the ever-present hazard to certain sensitive tissues if I came down hard on that ever-present top tube. None the lessI toured from Eugene, Oregon to San Francisco, California on that bike, and on sew-ups no less!
I rather quickly realized the error of my ways and remedied the seat tube length problem with a 52 CM (ctt) Raleigh Pro Mark IV two years later and a champagne-green 53 CM PX-10 in 1975. (I LOVED the handling of my second PX.... :-)
My problem has always been one of needing a long (54-56 CM) top tube with a 51-52 CM seat tube. Most frames that short have come with a a 53-53.5 CM TT, necessitating 12-13 CM stems in order for me to properly extend my proportionally longish arms and torso. (I have had two Raleigh Pros Mark IV, one PX-10, a KOF TREK 760, and an aluminum-framed and off-topic TREK 2000 with TTs in this 53-53.5 CM range. And those were the longest TTs I could find among the available production bikes. many bikes had shorter TTs...)
Since finding this list, of course, I have discovered the broad range of English path racers and 1930s - 1960s road racing frames with the "classic" relaxed geometry and long TTs that I seek. I have not yet had my Allegro out on any long, fast downhills (I need new whees to really let loose over 30 MPH safely, IMHO) but I will be really curious to compare its longer TT and relaxed angles to my late-1990s KOF Eisentraut, which tracks like a demon at 40-plus....)
For me, then, the seat tube range is far less flexible, as I am at my upper limit with a 52 CM center-to-top frame with 72 degrees parallel angles and a standard bottom bracket height. I might be able to ride as small as a 50 CM (ctt) seat tube but doubt that I would find many of those with a 55-56 CM top tube....
I am still looking for the "holy grail" in frame/bike fit, and the Allegro (72 parallel, 55 CM TT) may provide some answers that my Eisentraut (73 parallel, 54 CM TT) has not. Although it is really hard to criticize the way my 'Traut handles downhills.... :-)
Jon Spangler Almost feeling a 45-MPH wind in my hair in Alameda, CA USA
Writer/editor
Linda Hudson Writing
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-----Chuck Hoefer wrote.......
Message: 1 Date: Wed, 26 Jan 2011 19:37:17 -0800 From: "paccoastcycles" <paccoastcycles@sbcglobal.net> Subject: Re: [CR] Big frames ride better? To: "Tom Harriman" <transition202@hotmail.com>, <thomasthomasa@yahoo.com>, "Classic Rendezvous" <classicrendezvous@bikelist.org> Message-ID: <A412394FB8F34D9A9754BAE0F0924A21@ownerd556865ac> Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original
Tom Adams wrote:When I asked why, he said the bigger frames with the longer frame tubes would flex more and absorb more road shock.
My comment would be that it is not primarily the flex of the frame but the position of one's body and the distribution of one's weight with relation to the wheelbase that leads to comfort on the bike.
Chuck Hoefer
Pacific Coast Cycles
Oceanside, Ca