Determining the Year and Model of Your Steel Trek

Determining the Year and Model of Your Steel Trek
One often has to be a bit of a detective to sort this out.
For Year:
If you know the model number, compare the colors of your bike against the Models/Years/Color listing. This works only for Treks from about 1982 onward. The earlier bikes models were available in numerous colors.
Check the serial number of the frame. If a 7 digit alphanumeric, see the results of the Serial Number Decoding Project. If it is 6 digit numeric, in the range 000000 to 270975, go to the serial number page to get the year and model number. If it is 6 digit numeric higher than 270975, the year may be able to be determined from the Table II on the serial number page. Other SN formats are described on the serial number page.
Check the description of graphics by year in the timeline to match up your bike. Go to the brochures, the BikePedia.com web site (for 1993 and newer), the Trekbikes.com web site archives (for 2003 and newer) and perhaps the gallery for more detail. For some years, (generally 1981 and newer) color is telling. For many models, two colors were available, but only one color is pictured. The other is listed on the model description page or in the separate specifications table. If your frame has been repainted, you may be able to find the original paint inside the bottom bracket shell, seat tube, or head tube. Occasionally, a frame was returned to Trek for repainting. Trek would use the then current colors and graphics, not the original ones. This means that color and graphics can (rarely) be misleading as to year.
If your bike has a model name or model number, look it up on the Models/Year/Colors table to find the years your bike was sold.
Compare the components on the bike with those described in the brochures, if you think they may be original. (BTW - This is tedious.) Cranks and brakes (and often seatposts), are more likely to be original than other components.(Note: Trek occasionally changed the components from what were described in the brochures. Improved parts became available during the year or specified parts became unavailable. In the case of unavailable parts, Trek invariably substituted better parts.)
Date the components on the bike (if you think they are original), guided by the component dates page. Dated components most likely to be original are brakes, handlebars, cranks and seatposts.
For Model:
For some years, the model number (in the form xxx) appears on the bike. Easy - even I often get this right.
If the serial number is a 7 digit alphanumeric, see the results of the Serial Number Decoding Project. If the number is a 6 digit numeral, check to see if your serial number is listed on one of the serial number years.
Racing? Touring? Sport? Measure the chainstay length, from the center of the crank to the center of the rear dropout. A length of 43.5, 44, 44.5, up to 47 cm (the Model 720 and 85 620) typically is a touring model, racing models are shorter at 41 to 41.5 cm or so. Sport versions are somewhere in between, at 43 cm or so.
Compare the components on the bike (and frame colors on 81 and newer) with those described in the brochures. or in the descriptions on the BikePedia.com (93 and newer) or the Trekbikes.com web site archives (for 2003 and newer) web sites.
For many models, two colors were available, but only one color is pictured. The other is listed on the model description page or in the separate specifications table.
Eyelets on dropouts? (for fenders or racks) - typically none on racing models (except for the first 4 or so years), yes on touring models, yes on most sport models.
Rear derailleur cable routed above or below bottom bracket? See 1982 Timeline page entry.
Rear derailleur cable routed through right chainstay? See 1985, 86, 87 Timeline page entries.
Cantilever Brakes? = Touring model. Centerpull Brakes = Touring (early 1982 720/728). Sidepull brakes? This only rules out models with Cantilever brakes above.
Fastback seatstays with no TREK stamped on seat lug =TX900. (See Chas. Porter's bike in the gallery.) Also, the TX900 has three holes, of increasing size, in the top of the seat lugs and head lugs.
A seatpost diameter of 27.4mm indicates a Model 170. The Model TX300 is 26.8mm. All other vintage Treks are 27.2mm.
See Is it Columbus Tubing?