[CR]Bent seat stays, new and old

(Example: Framebuilders:Pino Morroni)

Mail-For: <classicrendezvous@bikelist.org>
Cmail: <classicrendezvous@bikelist.org>
From: "Alan Schaeffer" <alan@ordinaryextra.com>
To: <classicrendezvous@bikelist.org>
References: <a7.219e3190.2a315869@aol.com>
Subject: [CR]Bent seat stays, new and old
Date: Thu, 6 Jun 2002 23:29:36 -0400


> In a message dated 6/6/02 4:01:04 PM, NortonMarg@aol.com writes:
>
> << << It is a gimmick on seat stays. >>
> I don't buy that at all! Where is your information from? >>


> What don't you buy? It's styling, nothing more. I have two bikes, identical
> except for the curved stays on one and there isn't a penny's worth of
> difference between them.
> Phil Brown

I'll second that, Phil. My Hetchins Magnum Opus Curly, while smooth, is not different by virtue of the curves but the long stays and Champoinato del Mundo's. Other wheels demonstrate this.

On the other hand my Serotta Hor' Categorie with short stays and veloflexes is incredibly smooth. It has bent stays but there is a difference. When Serotta did their testing on the curved stays they did a lot of deflection tests on all sorts of bends and compared to a sampling of straight stay bikes. The results were uniform; none had any measurable characteristics distinguishable from straight seatstays, nor did they ride any different. That is where the "DKS" pivot a'top their dropouts comes from. This design produces a frame with a bent stay that can produce an honest 1cm of travel using their bent Ti stays. (And, NO there is no loss of energy due to flex. The guys in the Rocky Mountains all say it climbs faster!) Also, I seem to recall someone asking about curved carbon wishbone stays and that is indeed the next evolution of the Serotta design, WITH the pivots, of course.

Alan Schaeffer Danielson, CT

P.S While this is not all 'old stuff' talk I can't help thinking of all the informed hindsight that Hilary Stone brought us on alternative frame design at the cirque. It is part of my fascination with all this to ask why, and to see how it all works out over time. We all collect, ride, and talk about what not too long ago was being worked out by trying things and looking at the past and asking "why" and so on. While many a curve or diagonal tube has gone away, some good ideas persist. I am fascinated by the taper tube design of Gillott, and of Ben Serotta and I now also have a Tesch S-22, and I noticed the unfinished Richard Sachs frame on display at the cirque as well, ALL have taper tubes in the main triangle. I love this stuff! But, after all, WHY NOT?

BTW, any 58-61 cm c-c Gillott frames available really reasonably priced? (Doesn't need to have bent stays;^)