Ben <
[email protected]> wrote in message
news:<
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> So if it's steel (CroMo), it's brazed?
>
> In particular, I'm curious about this Miyata twelve speed I picked up.
>
> But I'm also curious if there is another way lugged steel frames are ever joined.
Some lugged steel frames have been made in a similar way to lugged carbon & Al frames, using
adhesive and metal lugs. Most notable UK example is the Dyna-Tech concept from Raleigh of
Nottingham; they also employed Ti and Al tubes in this way and sometimes mixed the materials to
give, for instance, a titanium/Reynolds steel hybrid. Peugeot used to (and might still) market
Reynolds-tubed frames employing their exclusive "direct brazing process". Not sure what this
entailed, but I've a feeling that the lugs may have been internal to give a very smooth external
appearance reminiscent of fillet-brazed products.
> > Brazing only works with steel frames. Lugged carbon fiber frames, for example, are usually glued
> > together.
They may use metal lugs (e.g. Look) or the lugs themselves may also be made of carbon, as is the
case with the Trek USPS team frames and the Colnago C40. Some glued and lugged frames also use a
threaded assembly, with the lugs and tube ends being tapped in order to screw together as well as
being bonded - I think this process is exclusive to the Alan company (best known for their
cyclo-cross machines) of Saccolongo, Italy, though. Bonded assembly used to be commonplace for alloy
bikes; welding is comparitively new, with Cannondale and Klein doing much of the pioneering work in
the field.
David E. Belcher
Dept. of Chemistry, University of York
