bikemig 

So I picked up recently what looks to be a 1985-1986 tretubi pinarello cross bike. I am trying to figure out the sticker. I can make out the words tubi and reinforzati. That means reinforced tubes, right? Does that mean that the bike has a double butted main triangle? Aelle was plain gauge right? Columbus SL, SP, and Cromor I believe are all double butted?

This is from 1989 but it has a good summary of the various Columbus steels.

https://www.equusbicycle.com/bike/co...umbuschart.htm

SJX426 

Have you checked the Pinarello catalogs?

scarlson 

Yeah, I'd wager on at least this much because of the "tretubi" meaning "three tubes" AKA the main triangle, and renforzati meaning butted.

I leave the rest to the experts as my Italian stops there.

T-Mar

This is a 1978-1987 decal for a tretubi Columbus SL or SP frameset. In other words, only the three main tubes are butted SL or SP, with the stays and blades some other material (often, though not always, Aelle). Builders typically transitioned from SL to heavier gauge SP around thge 58-60cm frame size.

The only Columbus decals during this period that did not not have the tubeset designation were SL and SP. Aelle came in a standard, plain gauge version and a butted Aelle R (Rinforzati) version. Cromor was also butted. Columbus' butted tubesets used a single butted seat tube, with the top and down tubes being double butted.

bikemig 

Oh yeah, this bike does not show up in the catalogs. This bike is a pretty rare bird and info on it on the interwebs is not that easy to find.

bikemig 

That's what I thought as well. But here's the kicker. The bike came to be with the wrong seatpost, a 27.2. A 27.0 didn't want to slide down either but a 26.8 works like a charm. Now I've seen one bike that I am fairly confident was made of columbus SP but it had a 26.8 seatpost. Possible? Or maybe the ears got pinched and this really is a 27.0? That may be the more likely explanation but the 26.8 fits in there pretty snugly once you tighten it down.

Here's the thread on the bike,

https://www.bikeforums.net/classic-v...clo-cross.html

It's not a Treviso, which is a full SL bike. The cross was sold to me as a Treviso and so I thought it was the "cross" version of the Treviso when I purchased it.

satbuilder 

I bought a Pinarello Italia model new in 1982 or 1983, I forget. It had the Tretubi sticker, as others have mentioned it was 3 main tubes butted tubing, This one came with Gipiemme dropouts, and was outfitted with Campagnolo Gran Sport and NR components. Still have the frame and some of the components.

Here's a link to what the sticker should look like: https://www.bikeforums.net/classic-v...nufacture.html

T-Mar

Oh, definitely. It's not uncommon for tubes to distort to non-round during the brazing process. Then there's scale and cinch slot burrs, which can result in an apparently undersize tube. Most reputable builders will ream/hone a seat tube after manufacture to bring it back to OEM spec, but a lot of the Italian builders had a poor reputation for frame prep.


However, it's also possible to distort the tube by installing and clamping an undersize post. This typically results in a cinch slot which is narrower at the top than the bottom. In such cases, I pry the cinch slot open with a wide, flat bladed screwdriver, so that it's wider at the top. Then I see what size seat post will install past the bottom of the slot,as that usually represents the true inner diameter of the tube.

bikemig 

This is the most likely explanation for why the 26.8 fits well. It likely is a 27.0 or a 27.2 and it simply needs some work to get the right size seatpost to fit. This is very useful; thank you.

T-Mar

In many cases, USA distributors did not import full products lines but only what they thought would sell in sufficiently large quantities. A lot of these "smaller Italian brands" had larger ranges than we realize, because they were not catalogued in the brochures issued by the American distributors.

SJX426 

I know the factory can be unreliable, got the wrong year from them based on a SN, but this might be different They might actually know!