Decoding Marin frame numbers.


Retro Newbie
There are 3 distinct sets of marin frame numbers between 1986 and 2004

So. ( dates stated are purely to identify the groups not an exact cut off).

1st Group A ....These are 10 characters long. Consisting of 1 letter followed by 9 numbers. ( roughly pre 91)

Example M885540375

M = factory of origin
88 = year of construction

Rest of the number seems to have no relevance to anything and i assume its marins code for batch etc. There is no consistent indication of model, month or date so far

So the above bike is a Marvel built 1988 bike.

2nd Group B..... These are 9 characters long. Consisting of 1 letter, followed by 2 numbers, followed by 2 letters, followed by 4 numbers. (Roughly 91 to 93)

Example M21BE0069

M = factory of origin
2 = Model code
1 = year of construction

The rest is marins code and i can find no relevance or pattern to show anything else.

In this era, with 2 letters the hierarchy is...

1 = team marin 2 = pine mountain 3 = eldridge grade 4=bear valley etc.

So the above bike is a Marvel built, pine mountain, from 1991.......No sizing in this code.

3rd Group C. These are 9 characters long. Consisting of 1 letter, followed by 2 numbers, followed by 3 letters, followed by 3 numbers. ( roughly 93 on)

Example F13DAC016

F = factory of origin
1= model code
3 = year of construction
C = frame size

In this era the, with 3 letters the hierarchy is....

1 = team issue 2 = team marin 3= pine mountain 4= Eldridge etc.

So the above example is a Fairly built, team issue, 1993, size 17"

The sizing code as far as i can work out is ...a=14 b= 15.5 c= 17 d= 19 e=20.5

Things to remember.....

1.Titanium frames are not included in this system.

2.Early monostay team issues carry their own numbering system, normally starting TET.....

3.There are a few team issues with 2 letters at the start of the frame number.....its not many, but my theory is marin did this to NOT upset their numbering system.....this was done uptill the point the code changed to the " group c" system (when team issues got the " 1" as a model denominator). Marin could not give it a "1" in the "group b" system as this spot was taken by the team model.

4.This system relates, i believe, to steel frames only. I did not look at alloy frames, but it seems they carry a slightly different numbering system.

The original post in 2008, didn't take into account the change in the number of letters, which is key, although several posters did point out the change in lineup would effect the model number.

The system above seems to resolve many of the issues encountered on the original 2008 posts.

Imo, the serial number is much more indicative of the model rather than the physical attributes of the frame, as marin did have a habit of having differing model specs dependant on world territory. So looking at a catalogue from the uk, could lead to mistakes if the bike came from america or japan for instance.

I have not found any real evidence of frame an frame stamped with an identifying number of an Eldridge, having factory decals of a bear valley on it.....i believe, imho, this belief has sprung from misinterpretation of the model numbers and the fact that some groups of frames are basically the same.

Like i said i hope this helps.
Thanks for putting this together. I just picked up a Marin at a used bike store, I think it is an 88 Palisades, based on the info you posted (thanks again) but there is only 5 digits with mine - the letter A, followed by 4 numbers. What do you think? Would love your opinion. I picked it up to be my gravel/sand camping bike - my touring bike can’t get wide enough tires on it for off-road camping.


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marc two tone

Retrobike Rider
Thats a nice rare beast.
Throughout the whole marin code system, the first 5 characters are the most significant, in any case.
The rest appear to reflect info around colour scheme, production details or Wednesday's lotto numbers.
Enjoy your bike!