Mongoose BMX Mid-School Serial Number Guide

If you're looking to find out the year of your mid-school 1990 to 1999 Mongoose BMX bike, this guide will help you locate and read the serial number on your frame.

Below we list the most common Mongoose BMX serial number formats, of course, given the many factories that made frames for Mongoose from 1990 to 1999, we've done our best to list them all. Sorry if your BMX serial number format is not included. We're updating information all the time.

The serial number on Mongoose BMX bikes does not indicate model.

Mid school 1990-1999 models

The serial number is located under the bottom bracket. The format is a string of numbers and letters.

A few early 90's models

Eg: LY89070817
The first two numbers indicate the year of manufacture.
For the example above 89 = 1989.

The third and fourth numbers indicate month of manufacture.

For the example above 07 = July.
The rest of the numbers are the frame number.
This frame was built July 1989. As this frame was built after May, the model year is 1990.

Eg: 10308572
The first number indicates the year of manufacture.
For the example above 1 = 1991.

The second two numbers indicate month of manufacture.

For the example above 03 = March.
The rest of the numbers are the frame number.
This frame was built March 1991. As this frame was built before May, this is also the model year.

Most Mid School Models

Eg: HFGG02906
The third letter indicates the year of manufacture.

For the example above G = 1997.

The fourth letter indicates month of manufacture.

For the example above G = July.
The rest of the numbers are the frame number.
This frame was built July 1997. This is not the model year.

A few late 90's models

Eg: ACL8H13356
The first number after the two or three letters indicates the year of manufacture.
For the example above 8 = 1998.

The letter directly after the year indicates month of manufacture.

A	B	C	D	E	F	G	H	I	J	K	L
JAN	FEB	MAR	APR	MAY	JUN	JUL	AUG	SEP	OCT	NOV	DEC

For the example above H = August.
The rest of the numbers are the frame number.
This frame was built August 1998. This is not the model year.

Alloy models

Eg: M8JI77870
The first number after the one or two letters indicates the year of manufacture.
For the example above 8 = 1998.

The letter directly after the year numbers indicate month of manufacture.

A	B	C	D	E	F	G	H	I	J	K	L
JAN	FEB	MAR	APR	MAY	JUN	JUL	AUG	SEP	OCT	NOV	DEC

For the example above J = October.
The rest of the numbers are the frame number.
This frame was built October 1998. This is not the model year.

Build Year versus Model Year

The serial number will only give you the bike's build year and month. This is not the model year or the year the bike was released and sold in shops. All bikes had a production lead time. If the frame was USA made, the production lead time was plus 3-6 months. If the frame was made in Taiwan this was plus 6-9 months. This is important if you are restoring and want to know what decals the frame would have originally had. The last thing to note is that the serial number on Mongoose BMX bikes does not indicate model.

Serial Number Examples

On each BMX Catalogue model page we summarise the serial numbers for that model. We also list a few example serial numbers to help you identify the date of your frame.