[Classicrendezvous] Re: Frame tubing & chrome

(Example: Framebuilders:Pino Morroni)

Date: Wed, 18 Oct 2000 12:07:43 -0400
From: Jerry Moos <moos@penn.com>
To: Hilary Stone <Hilary.Stone@Tesco.net>
CC: classicrendezvous@bikelist.org
References: <E13lupS-0001PO-00@bakery.tesco.net>
Subject: [Classicrendezvous] Re: Frame tubing & chrome

Very educational, Hilary, I didn't realize that the current 753 is thicker than the original stuff. Makes one feel a bit better about this tubeset, as most of the horror stories surrond the early 753 frames. This suggests to me a related subject - that of chrome. Is it safe to say that framebuilders have real concerns about chroming tubes 0.5 or thinner? Even though most frames use chrome only on lugs/forks/stays, it is my understanding that one usually chromes the entire frame, then polishes only the exposed chrome, while the unpolished parts are painted over. Are walls of forks and stays sufficiently thicker, at least at the bottom, that chroming or half chroming forks and stays is safer (presuming this much might be done without chroming the main tubes)? I presume that stainless steel lugs might give a similar appearance while avoiding the need to chrome the much thinner tubes, but don't stainless lugs discolor during brazing, requiring polishing afterwards? I also note that several of the remaining Italian steel frames, including Colnago, feature chromed lugs despite using thin walled Columbus tubesets. Have they devised a way to chrome the lugs without chroming the unbutted portion of the main tubes, or are they simply compromising durability for cosmetics? I realize these questions betray a general ignorance of chroming, but the only cure for ignorance is to ask.

Regards,

Jerry Moos

Hilary Stone wrote:
> Columbus SLX was 0.9/0.6 for all three main tubes ­ I think there was a
> lighter incarnation in its last few years but I haven't got my catalogues to
> hand at present.
> Reynolds 531 C was normally 0.8/0.5 top tube and seat tube, 0.9/0.6 down
> tube, 531ST was 1/0.7 for all three main tubes but many sensible builders
> used thicker gauge tubes in the larger frame sizes with either tubeset to
> increase stiffness. Indeed Gazelle in Holland were so skilful at this that
> their frames increased in stiffness from small to large. Fiets magazine had
> a complete set of Gazelle frames tested for torsional and bottom bracket
> stiffness. The largest frames amazingly were the stiffest because of
> Gazelle's choice of tubes and the smallest the least stiff. I nearly had a
> major row with the editor as I had written that larger frames were normally
> less stiff than small ones. He hadn't realised what Gazelle had done.
> 753/653 had 0.7/0.5 top and seat tubes with with o.8/0.5 down tubes in the
> later versions ­ it was onlu the earlier versions that were much thinner.
> Tange Prestige Super Lite was a really scary 0.6/0.3 for top and down
> tubes with triple butted seat tube 0.7/0.4/0.6. Standard road Prestige was
> 0.7/0.4 top and down with triple butted 1/0.8/0.6 seat tube.
> Columbus SP was 1/0.7 throughout all three main tubes but many builders
> simply used a SP down tube particularly in larger frame sizes to increase
> stiffness and the tubing sticker will not reflect this. This sort of
> practice was very common amongst the better more thinking builders. TSX had
> 0.8/0.6 top and down tubes with a 0.9/0.6 seat tube. The top and down tubes
> in this set had five spiral ribs running the complete length and the seat
> tube five spiral ribs on the butt. SLX just had helical ribs on the butts.
> SPX was the same as SLX except for being 1/0.7 throughout the three main
> tubes.
> Tony Oliver's book Touring Cycles published by Crowood has a very
> complete table of tube specs which were current around 1985 to 1990. It is
> still in print and I rate this book as one of the very best at explaining
> the whys and wherefores of speccing frame tubing. ISBN number is
> 1-85223-339-7. It is a shame that it hasn't been revised though.
> Hilary Stone
>
> ----------
> Jerry Moos wrote:
> >
>
> > Do you know the wall thicknesses of the other current Reynolds tubesets? Did
> I understand someone to say that Columbus SL was 0.9/0.6/0.9? Anyone know
> the
> thickness of SLX or TSX? The Columbus site no longer lists them.