So just like your fingerprints identify you, every bike has its own unique serial number assigned by its manufacturer. These serial numbers are typically six to ten digits long, and it’s this number that allows bicycle owners to track their bikes in case they’re lost or stolen. The bike serial number is a string of numbers that the bike company gives to your bike so they can identify details about the bike. Please feel free to add to, or correct this post.Wrapping Up Source: TrekBikes – Bike Serial Number

The first digit was a letter followed by a one digit number F2 meant June of '82 (using the same code as the bike models above) and these SN's were no longer found on the BB shell, but rather the lug behind it.Īfter 1980 it gets fuzzy for me since I lose interest in mongeese after 1980. This continued until sometime after March of '81 when the SN just went to one line, dropping the top line completely. Later the 'T' was moved to the top line, in front of the 'C' for both Team Mongoose and Supergoose: When the team mongoose model was introduced in '78, a 'T' was placed in a third row at the bottom, as shown in this pic (you can barely make it out, but it's there) The Racer-X models serial numbers started with an X (example: XB8, rather than CB8)

In early '76 a 'C' was added to the top line The earliest models ('75) were comprised of five digit numbers only (see pic) The next line was simply the sequentially numbered serial number. The third digit was the last number in the two digit year: The second digit was the letter code for whichever month the BB shell was manufactured: The first digit C stood for Chatsworth (California, where the factory started out) Typically, the Serial Number was on two lines, looking like this: (maker of Mongoose) used the same format for all of their bicycle brands (Jag, Roger DeCoster, Moto-Trac, etc.) with a few exceptions.

Mongoose bike serial number look up