Dale, Greg, et al.
I have a 56cm 1981 Bianchi Campione Del Mondo with a TreTubi Columbus decal on the down tube at the shift levers. When I bought the bike the seller though that "TreTubi" meant that it had triple butted tubes.
Being skeptical and having never heard of Columbus TreTubi tubing before, I went online as soon as I got home with the bike. I was a little disappointed when I found out that it meant "3 Main Tubes Columbus".
After several years of research on this bike it seems that the 3 main tubes are Columbus SL with Falck forks and stays (or that's what I want to believe). ;-)
The bike sat around for about a year or so before I took it out for a decent ride. I needed to change the bars, stem, saddle, pedals and brake cables before I rode it.
I was really pleased with it the first time out for a ~30 mile ride. It handles exceptionally well plus the ride is supper smooth. It's very light too, ~23 Lbs. with light weight clinchers and a Brooks Pro.
On an all Celeste ride last weekend with a number of Bianchi Cognoscenti, they suggested that the forks and stays on TreTubi bikes could have been made of anything Bianchi had laying around the shop including SL or SP tubes (à la Raleigh).
Back in the 70s, frames made with 3 main tubes Columbus had gold foil triangular decals. I remember some Italian made Torpados that we sold. We were told they had Falck forks and stays too. Also a few French made mid range Stellas had Columbus decals in French: "3 TUBES RENFORCES".
I suspect that the forks and stays on the Stellas were made of Durifort tubing. Durifort forks and stays with "3 TUBES RENFORCES REYNOLDS 531" was a common marketing practice in France during the 60s and early 70s.
The 7/10 (0.7mm/1.0mm) wall thickness on the 3 main tubes was the same on both Durifort and the Reynolds 531 tubes most frequently used on production bikes of that era.
There was probably little or no difference in the ride between an all Durifort frame and one with 7/10 Reynolds main tubes, just marketing mojo!
BTW, 7/10 was the wall thickness on Columbus SP main tubes too.
Chas. Colerich Oakland, CA USA
oroboyz@aol.com wrote:
>
> Greg wrote:
> << I'm the guy who mentioned Tretubi, in my original post. I was unaware that it was an indication of just three tubes of something. I have a Columbus Tretubi frame, and just checked it, and there is no indication which tubes are used, just says Tretubi. I always assumed these were three main tubes SL and some degree of downgrade on the stays and fork. >>
>
> I am fairly certain that "TreTubi" originally (1970s) indicated specifically SL/SP main tubes, then later other variations crept in...
>
> Dale Brown
> Greensboro, North Carolina USA