Originally Posted by
verktyg
The "Tretubi" stickers indicate that only the 3 main tubes are made with the designated type of tubing. The forks and rear triangle are made with some other kind of tubing - usually a lesser grade of steel (like seamed "Tubo Del Gas" Gas Pipe Tubing)!
OK- so in my post above, I explained why I think the fork of a Formula 2 Tretubi bike may actually be made of Columbus tubing. Here's an image of the fork tubing sticker of a F2T bike, images taken from this thread (post 24):
http://www.bikeforums.net/classic-vi...-d-italia.html
As you can see, the fork tubing sticker says: Foderi Forcella Bianchi Formula Columbus.
What does Foderi mean? I assume Forcella means fork. But in any case, unless Foderi means not-Columbus or something of the sort, the sticker certainly opens the possibility that it is made of Columbus (my guess is Cromor-level stuff) tubing.