when manufactured? s/n 91143

[artri]

Any idea when this bike may have been manufactured? I'm the third (at least) owner and the previous thought it was early 1990's.

The serial number on the bottom bracket is 91143. Thanks in advance.

[oliver1850]

Welcome to the forum. Hope you stick around.

I think 9 = 1989; 11 = November ; 43 = the 43rd frame built that month. I believe 1989 was the last year this system was used.

Take a look at the 1989 catalog in the catalog section. You may be able to tell what model you have by comparing details of your frame to catalog pics. I'd like to see better pics of yours, just because I like that vintage of Serotta.

[artri]

Thanks. I hope to stick around as well. I'll check back periodically and perhaps have some pictures in a couple of weeks after my big race of the season. I purchased this bike for triathlon training (found a great craigslist deal; seller was purchasing a new CF roadie and wanted someone to own this bike who would ride it regularly). So maybe I'll have some race picks in a couple of weeks.

[alexstar]

Nice bike, what tubing is it made out of? I also have (had) an '89.

[artri]

I have no idea what kind of tubing it is made from. How do I tell?

[alexstar]

There should be a small square sticker on the seat tube. It may say "Columbus".

[oliver1850]

It may be a repaint, missing the decal. What's the top tube decal say? If it's a Nova Special, it is Columbus SL; Nova Special X or Davis Phinney, SLX; Colorado would have the tapered Colorado Columbus tubes.

[artri]

No decal other than a "Made in the USA" sticker way down near the BB. The top tube says only "Serotta".

"Serotta" decals on top tube, down tube, seat tube, and chainstay. "S" logo stamped on rear brake bracket. "S" logo decal on head tube.

Those are all the markings aside from the serial number stamped on the bottom bracket.

[oliver1850]

Is the seat tube tapered in diameter or straight? The tapered one would mean it's a Colorado, and it would measure about 29 mm near the top tube and 35 mm near the bottom bracket. If it's tapered and has a fillet brazed BB shell, it's a Colorado II. If it has a lugged BB shell, it's a Colorado Concept (Tange Prestige tubing).

It appears that the rear brake cable is routed externally on the top tube. I think all Colorado IIs had it routed internally. Mine does, but it's a 1990. The 1989 catalog doesn't show it or state it definitely.

If the seat tube is not tapered, you would need to examine the inside for spirals in the tubing near the bottom bracket. Most likely would have to have the BB out to see them. If spirals are present, you have an SLX bike, which means it's a Nova Special X or a Davis Phinney. Probably can identify if it's a Phinney if you can accurately measure top tube and seat tube length. If there are no spirals, it's SL, and a Nova Special.

[artri]

No calipers. Other ideas to measure Seat Tube outside diameter? Lugged BB shell.

[oliver1850]

You can measure around the tube with a flexible tape, or use a string and mark off one loop with a marker, then measure between the marks with a tape or ruler. 29mm diameter will have a circumference of about 91mm, 35mm will measure about 110mm.

91mm = 3 9/16"
110mm = 4 5/16"

You should easily be able to see if the tube diameter changes from top to bottom.