Lugged Frame or TIG-ed frame?
By default, the bicycles shown on my site are TIG welded. Even though you may see this kind of construction almost exclusively these days on both steel and aluminum frames, you may not have know what it’s called. Here’s a photo of a Coto Doñana Vagabond showing a TIG joint — seat tube, top tube and seat stays.
But another way of “putting the tubes together” is with lugs. Lugs are sleeves that hold the tubes in place. Brazing rod is melted into the sleeve and becomes a very strong “glue” that holds everything together.
Is one method better than the other? It just depends on your preferences. Aesthetically, a lugged frame looks classy and elegant. With some creative filing and cut outs, lugs can become works of art. If you’re thinking about purchasing one of my bikes and want lugs, I’ll be glad to oblige. They are well worth the extra cost.
Structurally, either method is fine. Typically, a TIG-ed frame will weigh a little less because it has no lugs. In theory, the “butts” (more wall thickness at the end than the middle of the tube) can be a little bit shorter since heat from TIG welding is more localized. With a brazed, lugged frame, the heat spreads over a greater length of the tubing, so the butts may be longer. Longer butts add weight.
Lugs typically come in set angles, so this may an issue if the frame design calls for something unusual. Since TIG-ed frames don’t use lugs, any frame angles will work.
In an upcoming post, I’ll talk about the “miracle” of lugs, tubing and brazing rod.