Identifying an '80s Bianchi model and year
 

Recently picked up a mid-80s Bianchi roadie. It's a dull red color. Bottom bracket serial reads S4167C5.

Maybe a Stelvio? It looks a lot like this Stelvio-- https://www.bikeforums.net/classic-v...ing-bikes.html

It has a "Bianchi Special Columbus" badge on the fork, and a similar "Bianchi Special Produzione Columbus" badge on the frame.

Without wheels or a chain, the otherwise-complete bike weighs 14.8 lbs on my luggage scale.

It's no museum piece, with plenty of little chips and surface rust spots. (The irony of wanting to identify it is I'm not going to make any effort to keep it original.)

The rust (original?) calipers are Modolo. The (original?) pedals say Lyotard 82, though I see this was stock on an '85 Stelvio so the 82 is not the production year.

Will post pics in a follow up.

pics
 

https://cimg1.ibsrv.net/gimg/bikefor...f81985320e.jpg
https://cimg3.ibsrv.net/gimg/bikefor...21ee1d3bad.jpg
https://cimg4.ibsrv.net/gimg/bikefor...67ae0a01e6.jpg
https://cimg5.ibsrv.net/gimg/bikefor...a879b0b3bd.jpg

This thread has just about already answered it: https://www.bikeforums.net/classic-v...ecal-what.html

Tre Tubi Rinforzati means only the 3 main tubes are butted, so it's a midrange model. If not a Stelvio then something similar. Glad it's not a truly high end machine in such neglected shape.

I have seen other Stelvio frames with similar serial numbers.

Help me out here, someone more knowledgeable regarding Bianchi serial numbers. Does that count as a C.5 (March 1985 production) or an S4 (sometime in 1984 production)?
Would this frame be comparable in quality to my Campione d'Italia, which is also tre tubi?

Update, I've been riding this bike for a year and took it on two tours.

This frame has about a 57.25cm top tube, measured c-c, and a 72 degree seat tube angle. That shouldn't be a Stelvio; the review linked above says a 56cm Stelvio had a 55cm top tube and 74 degree seat tube angle. So it remains a mystery what model this was originally.

I really like the slack seat tube angle. It lets me get to KOPS before the saddle reaches the end of its rails. On my other old steel road frames the saddle is all the way back on the rails before I'm even at the KOPS "starting point." It's not good to hit the ending point before the starting point.

Lets hear a bit more about the parts on the bike. any pics of the top of the fork crown and stay caps? What's stamped on the dropouts? According to the catalog the Stelvio didn't use Special but Alle R, the over the BB cable routing is interesting too but this could simply have been a left over '84 frame

https://cimg4.ibsrv.net/gimg/bikefor...32afa3fc06.jpg
https://cimg5.ibsrv.net/gimg/bikefor...bd6ad4e0a6.jpg
https://cimg6.ibsrv.net/gimg/bikefor...c18d5d8826.jpg
https://cimg7.ibsrv.net/gimg/bikefor...3e926c34e1.jpg
The rear dropouts have BIANCHI stamped on each one, all caps, and no other markings.

Here's the fork crown and tops of the seat stays (is that the "stay caps"?) I don't see any markings other than the prominent Bianchi "B" at either spot.

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Careful with those old Gatorskins, the sidewall on the front tire looks like it's going to give way.

Are you measuring the ST angle off of the TT angle, or perhaps on a not-so-level surface?

Did you measure the STL as center-to-top or C-C?

I can't really imagine this particular Bianchi having a 72-degree ST angle.

I measured from the ST to the TT with a protractor.

To double check the protractor, which is not super easy to read, I did some tape-measurements and some trig to compute a STA. These are all c-c, rounded to nearest cm:

ST = 56cm
TT = 57cm
DT = 61cm
HT = 9cm

The HTA is around 74 degrees. Based on that, the math projects a STA slightly below 72 degrees. Close enough to the protractor.

This frame has no other "touring" features -- no canti brakes, minimal bosses (sadly) and shorter chain stays; the 28mm rear tire is within 1cm of the seat tube. So it's a roadie, it's just got that low, lax STA. It's an oddball.