Fillet brazed frames

[biglev]

The old USA-made Cannondales used to have really smooth (welded aluminium, I know) joints. Does anyone know how this finish was achieved? I guess with some sort of sander or grinder, but would it have had to be done by hand?

Slightly off-topic, but it shows that there can be some nice-looking TIG welded joints.

it was done the same way as the steel frames with a dyna file (http://www.abrasivesupply.com/Dynabrade ... /40321.htm) and and then strips of emery cloth and hand finished. I think in one of the 1980's Cannondale catalogs (1987?or was it Klein) there were pictures of them doing it.

 

[minor_LEGEND]

Personally I think I prefer the look of TIG oddly, despite it's popularity in mass production & far eastern commonplace however my ride is fillet brazed.







It does lead to stunning lines IMO.

 

[firedfromthecircus]

Even now fillet brazing has it's place. As has been mentioned a large number of custom builders still braze and it is also useful for repairing frames that have cracked in the heat affected zone of their tig welds!

Modern tubesets have been developed that react well to the high heat of tig welding because tig welding is cheaper. Not because tig welding is better. I am not claiming a degree in metalurgy, but as someone who brazes I can guarantee that a properly brazed joint has plenty enough strength for a bicycle frame.

As for production frames that are brazed, modern Pace frames such as the RC 104 are brazed and as mentioned Saracen did a brazed Kili for 1989.

Pace.

Saracen.

And not made out of shabby tubing either.