Originally Posted by
unworthy1
and Excell and Mannesmann and "something Japanese that used a dragonfly"...but since you asked a simple honest question now you have to be prepared for the complicated, nuanced answer: there's more to tubing quality than: "this is good, and that's crap."
It's often true that the best work of a craftsman or factory will only be made with the "best" or at least the "most expensive" tubing available. But there are so many examples of high grade and wonderfully riding frames built from the "lesser stuff" that you have to keep an open mind about what's "best".
In most cases, it's the decision of the builder as to what's the best tubing for the job at hand: some famous builders (Poliaghi and Eisentraut for example) are noted for mixing tubes from various sources.
I believe Excell actually sourced its tubing from Mannesmann. Mannesmann made very high-quality stuff - I believe mainly supplying raw material to other folks who drew it into bike tubing (including Columbus).
Lots of custom builders mix tubing. Sometimes depending on what they were trying to accomplish and sometimes depending on what they had available. Sometimes, the absence of a tubing decal is a tip-off, but not always.