Trek Frame Serial Numbers
to Late 1980 | Late 1980 to Late
1986 | Late 1986 to 1999+
Foreign Built After 82 | Jazz by
Trek | Missing Serial Numbers
Serial Number Location
Trek frame serial numbers (SNs) are typically stamped
into the bottom of the bottom bracket shell. In the case of some early
80s Treks, the number is under the plastic cable guide on the
bottom of the shell. Just remove the plastic cable guide to see the
number. The other place Trek (or their subcontractors) stamped the SN
is at the lower end of the seat tube.
Note: The SN on your original sales receipt may not
match the one on your bike. Sales persons sometimes had difficulty reading
Many early Trek bottom bracket shells have a one or
two letter code stamped separately from the serial number. This was
made by the individual framebuilder to mark his/her work. On some bottom
brackets there are two codes: one indicating the maker of the main triangle
and the other for the maker of the rear triangle or perhaps the person
who cut and shaped the tubing, if not done by the framebuilder. If you
know which mark was used by a particular craftsman, please let me know.
The dates coded in the serial numbers, or the dates
inferred from the numbers, are dates on which the new frames were stamped
with serial numbers (serialized). These dates are not necessarily
the same as the model year of the frame. At some time late in each
year (beginning generally September or October) the frames produced
were created from designs, and painted with colors, for the next year.
Hard to read?
Trek serial numbers can be hard to read. Clean the area
well, and use lots of light at various angles. A suggestion by J. Hansen
can help you read a serial number:
Serial Number highlighted with
red wax. Click on image to see an enlarged version. (Photo by
"Rub the area with candle wax of a color that contrasts
with your paint. Lightly wipe it off with a rag. The wax stays in the
indented area of the S/N. Now you can easily read the number. I have
included a photo of the results from my bike. In this case I used a
red candle to make the serial number stand out. Note that even with
the serial number filled with wax, the leading "0" is almost
Serial Number Descriptions
The serial number descriptions are divided into five
categories. Click on the link below to go to the appropriate category.
to Late 1980 | Late 1980 to Late
1986 | Late 1986 to 1999+
Foreign Built After 84 | Jazz by
Trek | Missing Serial Numbers
PRIOR TO LATE 1980
Before late 1980, Trek used an alphanumeric serial number
scheme. Each seven-character number consists of three letters mixed
with numerals. The serial number list and the code for the list are
not available from Trek (but hope springs eternal). In the meantime,
we have the results of the serial number decoding project:
Serial Number Decoding Project
Nearly two hundred Trek owners submitted their
frame's specifics to help decode Trek's first serial number system.
Our thanks to these generous cyclists. Trek used this system from
1976 to late 1980.
A variant of this first system was used in 81
and perhaps 82 for some frames. See ****
year exceptions below.
These serial numbers have seven characters, in
the form L N L N L N N, where L is a letter and N is a number.
Here are the results:
The first letter is the model designation.
The letter code indicates frame model, which would include bike
models made from that model of frame.
A = 310 (see note *
B = TX200 (see note **
C = TX300,
D = 530,
E = TX500,
F = 510 (**** see
year exception B below),
G = TX700 and TX770 (see note***
H = 710,
I = 730,
J = TX900.
K = 910,
L = 930,
M = 412 and 414 (****
see year exception A below),
N = 610, 613, and 614 (****
see year exception
O = 950. (**** see
year exception D below). This numbering system
was used for custom 950s. This letter may also have been used
for custom 750 frames. If you have a leading O (Oh) serial number
on a frame with Reynolds 531 stickers, please contact me (Skip).
This applies only to serial numbers in the form LNLNLNN where
the first letter is an O (Oh). This does not apply to the all-numeric
serial number form that began in late 1980. These begin with
a zero not an Oh. For these all-numeric numbers with a leading
zero, see LATE 1980 to LATE
A couple of serial numbers have been submitted
that are missing the first letter. This letter designates the
model. The remaining six characters are typical. It appears
that some custom frames were built that did not fit within the
standard model description. For example, a 710 frame made with
Columbus tubing instead of 531. What leading letter to use?
Perhaps it was just left blank?
The first number is the frame size, where
1 = 19.75",
2 = 21",
3 = 22.5",
4 = 24",
5 = 25.5",
6 = 57.5 cm (ctc) or indicates a custom size. (See Year Exception
7 = 59 cm (ctc) or indicates a custom size. (See Year Exception
9 = 63.5 cm (ctc) or indicates a custom size.
(See Year Exception D.)
The second letter represents the month
the frame was serialized:
The second number is the last digit of the
year, 6, 7, 8, 9 (for 197X) and 0 for 1980. See
note below, ****,
for year exceptions. Again, this
is the date of serializing, not necessarily model year.
The last three characters - The final letter
ranges from A to Z and the final two numbers go from 01 to 99.
The last letter might be a run designation, with the last two
numerals the frame number in that run? Alternatively, the letter
extends the range of the character from 0 to 9 (if a number) to
1 to 26. This gives a range of 2600 for the 3 characters. Any
other ideas for these last three characters?
The rest of the code defines time to a month.
Perhaps once Trek was nearing more than 2600 bikes/frames of a
given model per month, a new serial number scheme needed to be
developed. Hence the change to the sequential system that was
started in late 1980.
is no Model 310 in the brochures on the site; however, a frame
has been reported that has Ishiwata high tensile double butted
main tubes with the SN A4F9H67. It has touring length chainstays.
According the the SN, it apparently was made in June 1979, after
the TX300 is no longer in the brochures, but no similar frame
is listed. Another small mystery; for now we'll call it a 310.
** One interesting
variant of the SN code has been submitted. It has a leading
B and has eight characters instead of the usual 7 (B4K6B109).
It has SunTour dropouts, and had a partial tubing sticker that
included the text "TENSION BUTTED". The date from
the SN is Nov. 76. Probably a TX200 with an extra character
in the SN.
frames with a leading serial letter of G have been reported
with Columbus tubing stickers. TX700 frames were available as
special order, with Columbus tubing instead of the specified
Reynolds 531. These bikes were designated as Model TX770. However,
this model did not appear in any of the Trek brochures on this
A. Serial numbers beginning with M or
N (41X and 61X bikes or frames) seem to have a different meaning
for what normally is the year digit. The year digit is the fourth
character in the number. In the 50 M and N serial numbers that
have been sent in by owners, the year numbers go from 0 through
9. The remaining part of the serial numbers seem normal.
According to the brochures, Trek did not make
41X and 61X bikes or frames during 76, 77, 78, and 79 and also
not in 83, 84, 85, 86, 87, 88, or 89. These serial numbers apparently
do not follow the year convention used for other Trek models.
It is likely these frames, SNs beginning with M or N (Models
41x and 61X), were contracted out or were made in a separate
Trek facility, and were given the old serial number form so
as not to interfere with the sequential numbers being assigned
by Trek in their main shop, which began in late 1980.
This variation to the SN system may have been
done to extend the numbering system. By using the fourth character
as an extension of the last three, the serial numbers could
be extended from 2600 possible combinations to 26,000 for a
For M and N leading serial numbers, if the TREK
letters on the seattube have no colorwrap behind, the bike is
from 1980 or perhaps 1981. If it has a colorwrap, the bike is
probably from 1982.
B. Serial numbers for four model 510 frames
(with a leading F) have been reported that have similar unexpected
year dates. (Our thanks to Rich Ferguson, Fred Gomez, and Chris
Tank.) The fourth characters are 2, 3, 4, and 5, there may be
more. The frames have the early TREK graphics on the seattube.
These frames may be related to the M and N leading serial number
bikes in the section above.
C. One early TX700 (leading G), an evaluation
frame sent to a bike shop, had a 4 in the year digit. Another
impossible year code. This 4 may signify an evaluation unit.
D. Trek used this form of serial number
(leading O "oh") for their custom-made 950 frames.
The production (non-custom) frames were numbered using the late
1980 to 1986 system described below. Three (leading O) 950 frames
have been reported that contain unlikely year codes of 5, 6
and 7. Model 950 frames were not made in 1975, 76, or 77, but
only in 1980, 81, or 82, (according to the brochures). Another
950 frame was reported with a 0 (zero) in the year code, but
was painted as a 1982. From the geometries, they all appear
to be custom frames.
When a Trek frame was repainted by Trek, an additional
set of numerals was often stamped into the bottom bracket to indicate
the frame was repainted. These numbers were usually four digits,
in the form NNNN.
1980 TO LATE 1986
Late in 1980, Trek changed to a new numbering system
for their frames built in the U.S. The frames were numbered sequentially,
beginning with number 000001. The record of the assembly runs was documented
in a handwritten journal. Trek (Kevin Tita) graciously provided a copy
of the journal for this web site. The list ended in November of 1986
with number 279975. This serial number system actually extended through
at least 1997 (see Table II below).
The journal includes run number, model number, frame
size, and serial number range. Incidental information, including dates
and comments on the frames, appears sporadically through the journal.
A "run" was for a particular frame size and frame model.
We all owe thanks to Luker White who
generously donated his time to convert much of the paper list to digital
These data were mined to produce bike production by
model for each calendar year. The results can be seen on the Trek
Bike Production by Model, Late 1980 through 1986 page.
Click on the date link
in Table I below to go to the detailed serial number information for
Table I - 1980 to 1986
Notes for Table I:
- Table I contains dates of frame serializing, and
are not necessarily model year. At some time late in each year
(generally September or October) frames were built for (then painted
with colors for) the next model year. This journal information is
summarized by year in Table I. The year designations in the table
are approximate; not all of the runs are sequential in time. This
may be a result of subcontracting some frame fabrication.
- For some years, the model number given may be the
lowest number (or an X00 number) for a series of models that have
the same frame. For example, a 1981 frame appearing on the list as
a Model 610 could have been built into either a 613, 614, or 616 bike.
- Some of the Model 170 serial numbers are 6 digits
but do not follow the numerical sequence. A future task is to sort
170 numbers. Some of these are presented in the 83, 84 link
at the bottom of the table.
- Some early and mid 80s bottom brackets were marked
with 58TSI or 60TSI. In the early 1980s Tim S. Isaac designed new
lugs and a new bottom bracket shell for Trek. The new bottom bracket
shell is typically marked with 58TSI (or more rarely, 60TSI). This
designation is not part of the serial number but is a model number
of the shell. The TSI are Tim's initials. The 58 or 60 refer to the
angle between the seattube and the downtube.
- Some frames in this period have a leading "A"
before the 6 digit number. This may be more prevalent on lower level
models. The "A" may not be part of the SN. Just disregard
it when looking up the number in the tables below.
- Frame Sizes in the SN list below are as given on
the paper copy. For some entries, only a two-digit number was given,
the extra 1/2 or 3/4 inch was dropped. So - an entry of 22 inches
really means a 22.5" frame size, 19 means 19.75", 25 means
- The list has two major gaps, corresponding to missing
pages. Page 9 ends with SN 027870 and the next page starts with 029118.
Page 61 ends with 210065 and the next page starts with 215226.
- The SN list for 1986 has some serial number ranges
with annotations about POs (purchase orders) to "Merida".
These are for Model 800, 830 and 850 mountain bikes and Model 300
road bikes. These were made late in the year, so they probably were
all 1987 models. At least some of these were provided to Trek as "frames
only". One reported SN in these ranges, for an 850, was prefaced
by the letters TML. From the serial number list, the number of Trek
frames or bikes made by Merida late in 86 totaled at least 8251.
Merida is a Taiwanese bike company that was
established in 1972. It is currently a major, worldwide player in
the bicycle business. See http://www.merida.com/
for information on this company.
LATE 1986 to 1999+
This 6 digit (7 digit beginning in 1993) code extended
into at least 1999, at least for some models (generally mid to upper
level and made in the US). The number may or may not have a leading
zero, making the six digits into seven digits prior to 1993. The model
is not available for these numbers but the year can be determined or
estimated from Table II below. The information in the table is from
serial numbers submitted by site visitors. Our thanks to them. In contrast
to the serial number dates in Table I above, the years in Table II
represent model years, not the date the serial number was applied.
Table II - Model Years 1987 to
Serial Numbers Include
270821, 284237, 284335, 293788,
301294, 304445, 304940, 307880, 308292
309634, 316981, 319336, 335133,
346451, 347944, 356837, 360384, 364072
369203, 379079, 391236, 406793,
427402, 438108, 455267
458184, 513747, 532881, 563678
579529, 629426, 653761, 669753,
771408?, 811550, 819194, 840762,
873805, 883719, 900224
971670, 1027164, 1035688, 108?734, 1106529, 1109196, 1116394,
1164917, 1269067, 1287883, 1306226
1331934, 1383671, 1406630, 1431480,
1544446, 1649278, 1878372, 1955570
1876296?, 1963294, 2008374, 2063546
2090413, 2140321, 2172336, 2195013
FOREIGN-BUILT FRAMES AND BIKES AFTER 1982
Three different serial number forms have been submitted
for 1983 Trek Model 400 frames. One, marked "made in Japan",
begin with JS followed by six numerals. The SN was located on the
bottom of the bottom bracket. A second serial number is 81765. According
to the Trek-provided SN list, this corresponds to a 22" (22.5")
Model 400 frame made in 1983. This SN form is for frames/bikes made
in the US The number was marked on the bottom of the bottom bracket.
The third number is 403300950, which indicates foreign built, but
the nation of origin sticker was missing. This number was marked
at the bottom of the down tube. It is likely this 400 was made by
the same manufacturer as the 1984 bikes described in the paragraph
below. For the 1983 Model 400, it appears Trek used three sources
for their frames or complete bikes.
Several 1984 Trek 460s, 420s and 400s have been
reported with 9 digit numeric serial numbers stamped on the lower
seat tube instead of on the bottom of the bottom bracket. These
frames, or complete bikes, apparently were made in Japan by an outside
contractor. The numbers submitted are in the range of 401000000
An 8 or 9 character alphanumeric code was used for
mid- and low-level frames subcontracted in Taiwan. Most of these
bikes were labeled "Made in Taiwan" (although the sticker
often is easily removed). This form of serial number appears to
have been used during the period 1987 to 93. The number leads with
a T (for Trek?) then a numeral, one letter or two, then five (sometimes
4) numerals. Sean Hickey suggested the first numeral is the year
of manufacture, and the letter is the month of the year (A - L).
This is confirmed by serial numbers that were submitted by other
Trek owners. If there are two letters after the year numeral, the
first is the month. The second runs from A through at least Y. It
might be a way of extending the 5 digit number series by a factor
A later 8 and then 9 character alphanumeric SN scheme,
used beginning in about 1989, also begins with a T (for Trek?).
These later T numbers were used on lower level subcontracted frames
but do not follow the 2nd and 3rd or 3rd and 4th character date
Beginning in about 1993 (model year 94), an 8 character
alphanumeric code was used for some bikes. It begins with G and
another letter (e.g. GN, GQ, GR, GS, GU, GV, GW, GY and GZ). These
are followed either by: 6 numerals, or a numeral and a letter followed
by four numerals. The first numeral in the SN may be the year of
JAZZ BY TREK
Jazz is a line of foreign-built, entry-level bicycles
that Trek sold in the early 90s. (See the history
page for a bit more info and the brochures
page for a 93 catalog). There seems to be at least three serial
- A Flipside model had the serial number JT0116 stamped
on the bottom bracket shell. The JT probably stands for "Jazz"
and "Trek". The numbers may be the sequential frame number,
beginning at 0001.
- The second type is a 10-character serial number.
The first two characters are letters which are followed by eight numbers.
Examples are JT09010099 and FI08003231.
- A Latitude model has a 10-digit, all-numeric serial
number: 1230707859. This number also was stamped on the bottom of
the bottom bracket shell.
These three serial number forms may mean that Trek used
at least three subcontractors for the Jazz line.
MISSING SERIAL NUMBERS
A few owners of early
Treks, mostly, from 1976 through the early 80s, report their frames
are not marked with serial numbers. A past Trek employee wrote that
the police in the Madison and the surrounding area said TREK was famous
for bikes with no serial numbers. Seems hundreds didn't get any numbers
at all. The serial number guy just missed a few?
Three other possibilities:
1. In the early years Trek allowed, and even encouraged, their workers
to use company equipment and materials to build personal frames after
hours. These frames often were not serialized. The practice stopped
after production was increased, resulting in little available down time
for the equipment. 2. The serial number on a repainted frame that was
not first stripped, may disappear under the new paint.
3. The number is under the plastic cable guide attached to the bottom
of the bottom bracket shell.
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