Originally Posted by froze
Wow what a load of crap some have so happly donated here!!! ........... and some such as Colnago used a tube with a fluted shape to it and they had lugs to fit it. Making a lug of various shapes, sizes and designs is not a problem with wax castings, but to keep complication down they limited it to 2 different tube diameters and limited it to tube shape-mostly round except for the Colnago.
Then Astra said that lug construction is heavier, problem is with a welded frame they have to have the ends thicker to buttress the tube when it's welded so the thicker ends almost negate the lugs weight and still is not as strong as the lug.
Well, yours is not exactly stink free.... The 'fluted' Colnago tubes are round on the ends where thay plug into the lugs,except at the base of the seattube where the rounded section is slightly ovalized. Identically butted tubesets are used in both lugged and tig welded construction, meaning that a welded one isn't necessarily thicker or heavier. I could go on,but..............