Mike Kone wrote
>
> Am I missing something here? Isn't 531 SL just a 531 tubeset
> with very thinwall tubing packaged as such by Reynolds?
>
> In the early days of French touring bikes (yep, there I go
> again), builders built frames with 5/10 or even 4/10 tubing.
> In fact, they were using this lite stuff even in the 30's.
> So while it was not labeled as such, the very light 531 tubes
> were available for many years before they were called SL.
>
Mike,
Yeah I know the tubes were drawn that thin before they made a special decal to announce it - but still - LOTS??
Do we have any idea of the numbers of frames made of the ultralight tubes in those earlier decades? Maybe Jan Heine has an idea of how many builders, how many units? I'm guessing, outside of the Technical Trials and a few "specials" made for weight-obsessed clients, not that many. My hypothesis is: The thin tubing bikes got media attention out of proportion to their market share.
Tubing that thin, aside from the skill required of the framebuilder, makes for a whippy frame by anyone's standard. Now I happen to like a whippy frame, don't get me wrong - but most riders don't (or at least think they don't, because they've been told they don't; a whole nother can o' worms). Result is, whippy frames can be a hard sell in the marketplace. And with normalized (non-heat-treated) tubes like 531, the fatigue life was probably finite for those thin tubes, for all but the lightest riders. I.e. they are more or less guaranteed to break someday, if ridden consistently (not hung on the wall as art).
Has anyone here actually weighed an Herse frame that was under 4.5 pounds (the range a frame with .4 mm tubing will be in, IIRC)? (Not counting Technical Trials frames, Jan, those are in a class all their own!) I know 4 lb Herses probably existed, but I think they must have been few, AND most of them have broken by now if ridden a lot.
In case anyone thinks this sounds like sour grapes, I made lugged steel frames under 2.5 lb. (with .3 mm tubing) in the CR time period or a little later. My own #1 road race frame from back then weighs about 4 lb - and I am a 6'2" 240 lb. "sprinter", and still riding it. Not saying it can't be done. Just guestimating that it was always kinda rare.
Mark Bulgier
Seattle WA USA