Ahh, Light bulb goes on! Yes, Charles is describing what I was getting at, somehow a difference in ride quality in a larger frame, but as he astutely points out, the difference may be that older frames with slacker angles need a longer seat tube to be approximately the same distance from BB to saddle. And as I think about it, the frames I am thingking of when I say "ride nicer" are indeed some of the Greybeards in my fleet, the Algurn and Holdsworth Sirocco, both from the 50's, although the more "modern" Silk Hope ('74, Dale?) has the same elusive "feel". All three are at the top end of my size range.
BTW, this is not an absolute rule true for all bikes. I've had some upper size range frames that were dogs. It just seems like the slightly larger bikes on average ride slightly "nicer" than the smaller bikes. And it may be that "nicer" as I get older may be more relaxed and compliant, as opposed to zingier with razor edged turn carving ability.
Thanks, Charles, for saying much better what I was trying to say.
Manhattan, KS USA
From: Charles Andrews <email@example.com> Subject: Re: [CR] big frames ride better--from an average sized rider.. To: firstname.lastname@example.org Date: Wednesday, January 26, 2011, 5:59 PM
I've followed this thread with some interest. It is an ongoing amazement to me that I keep learning more and more about sizing and fit even after so many years riding a road bike.
I've found that older bikes with slack angles, lower bb shells and longer stays and top-tubes tend to be very nice in slightly larger sizes. If my racing size is 55cm c-t, a 57-58 cm c-t in a frame of this older style will not only be more comfortable for me in general, especially on longer rides, but overall handling seems...easier. I notice that my position on these larger frames always seems ideal with regard to weight distribution and body position, although I suppose you could achieve the same thing on a smaller frame. I've tried, though, and it's not quite the same, even on a smaller frame with the older geometry.
I recently bought a 58cm c-t Bianchi Competition from the early 1960s, with just a little seatpost showing when it's set up correctly for my leg-length. It rides like a perfect ocean-liner, with plenty of refinement, and I don't especially notice that frame is a bit big. Sure, a 57 or 56 would probably feel better in some ways, but a bigger frame of this kind is perfectly fine too.
Problems crop up for me with later-style frames, with steeper angles, higher bb-shells and shorter stays and top-tubes..I really notice it when those frames are even slightly outside my ideal size of 55-56cm c-t seat and 55-56cm c-c top. I've bought and sold a lot of really nice criterium bikes of this sort..they never seem to feel right. They just feel too big..as if the bike's riding me instead of the other way around. Maybe there's something less forgiving in general about these later, more aggressive frames. They're certainly rideable..the effect can be subtle. But I'm at the point where I don't have any even slightly oversized bikes in this later style.
It's because I'm getting older..but I find those later aggressive criterium bikes to be distinctly unappealing. Such bikes seem to have been designed for a lot of seat-post showing, and long stems. Ride one in a size larger than ideal and they just don't feel right. The earlier road geometries, with the long stays, low bb and slack angles, esp slack seat-tubes, feel better and better as the years go on and are more forgiving of variations in fit.
Charles Andrews Los Angeles
It is impossible to begin to learn that which one thinks one already knows. --Epictetus