Throwback Thursday: Mountain Bike Welds from 1988

Richard Cunningham shared his frame-building knowledge with a lesson on the different ways of putting frame tubes together. In this picture Richard showed and described TIG welding: “Recognized by its fish-scale bead pattern, TIG welding is the most popular method of joining tubes together when the ultimate in strength is wanted.”

“Aluminum welds: Though most manufacturers cover their aluminum frames with heavy coats of paint, you can identify good aluminum welds by the large evenly spaced and uniform bulges of the bead.”

“Lug construction: By using lugs, a manufacturer gets a ready-made joint that only has to have the tubes inserted. Brass is then drawn into the gap between the lug and the inserted tube to cement them together.”

“Fillet brazing: Considered an art by most mountain bike aficionados, filet brazing is done by building up brass around the joint to form a seamless-looking juncture. Careful filing will result in good looks.”

“Adhesive bonding: Bonding is identical to lug construction. The only differences are that aerospace adhesive is used in place of melted brass, and the tubes slip over instead of into the lugs.”

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