Mongoose Bike Serial Decoder

Posted : admin | On 17-08-2021

The first thing everyone wants to know when the buy a second hand GT BMX is ‘how old is it?’ Reading the GT serial number and finding out the build date is an important part of any BMX restoration. Once you now when the old GT BMX bike was built it’s much easier to find out what model it is and also look at the original parts lists and colours from the bike makers catalogues.

A while back I spend some time investigating how to read mid-school and new school serial numbers on Mongoose BMX bikes. After buying and restoring a number of older mid-school and new school GT BMX bikes I also need to to figure out how to crack the GT serial numbers to get the same build date information. Jul 25, 2010 Mongoose frames manufactured in 1975 to early 1976 had five-digit numbers hand-stamped on them, starting with 10000. If the serial number of your Mongoose has a number such as 11994, with no letters in or near the number, it is likely a frame from 1975 or early 1976. Scan the area to see if the letter C is etched above the five numbers.

A while back I spend some time investigating how to read mid-school and new school serial numbers on Mongoose BMX bikes.

Mongoose Bike Serial Decoder

After buying and restoring a number of older mid-school and new school GT BMX bikes I also need to to figure out how to crack the GT serial numbers to get the same build date information.

It didn’t take long to realise there were many similarities when looking at GT serial numbers and Mongoose serial numbers. The placement and sequence of the numbers is stamped in the same place under the bottom bracket. Many of the GT serial numbers start with the same letter sequence. After a bit of digging around online I soon realised that GT BMX bikes and Mongoose BMX bikes were owned by the same company and also made in the same factories in Taiwan. In fact look closely at many Mongoose and GT BMX’s from the around 2000 to 2010 and you’ll see many similarities in frame design and geometry. This is probably not true for all of the bikes in either range, but there were a number of bikes that were identical apart from the logo stamping. Anyway that’s a post for another time.

As with the Mongoose serial numbers there are many posts from forum members around the world on old-school GT serial numbers, but very little on mid-school or new school.

Of course there are also many variations in GT serial numbers and I have focussed mainly on cracking the new-school numbers for now. That is bikes made between 2000 and 2010, and those bikes made in the Taiwan factories with specific serial number sequences. There will be bikes that are different, if you have any examples of where this crack doesn’t work, add a comment below.

GT serial numbers are usually found stamped on the bottom of the bottom bracket of your BMX. This is not always the case and there will be some bikes that do not fit into this formula.

For mid-school GT BMX bikes built in Taiwan through most of the 90’s with a serial number that begins with 4 letters before the series of numbers. The 3rd letter corresponds to the year of manufacture.

1991-2000 – 4 letters at beginning, 3rd is year

A B C D E F G H I J
91 92 93 94 95 96 97 98 99 00

The 4th letter indicates the Month

A B C D E F G H I J K L
Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec

A few examples are:

HFGB00000 – 4 letters, GB are the dates. G is the year (1997), B is the month (Feb)

HFBH00000 – 4 letters, BH are the dates. B is the year (1992), H is the month (Aug)

For new-school GT BMX bikes built through most of the 2000’s with a serial number that begins with 5 letters. The 4th letter corresponds to the year of manufacture and follows on from the mid-school serial numbers.

2001-2010 – 5 letters at beginning, 4th is year

K L M N O P Q R S T
01 02 03 04 05 06 07 08 09 10

The 5th letter indicates the Month

A B C D E F G H I J K L
Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec

A few examples are:

HAMRF00000 – 5 letters, RF are the dates. R is the year (2008), F is the month (Jun)

HAMOI00000 – 5 letters, OI are the dates. O is the year (2005), I is the month (Sept)

Please note: The GT serial number will give you the build date of your GT BMX. Frames were normally manufactured the year before being sold in bike shops. So a build date on a frame of 2003 usually means the bike was sold in stores in 2004.

If you want to know more about the GT BMX you have, visit our BMX Catalogue website. You'll find all the original catalogue info you need including original parts lists, specs, colours and photos of restored bikes.

There is no function for me to reply to comments left on this post.If you have a BMX and don't know what the serial number means. I might be able to help. Go to our Facebook page https://www.facebook.com/rerides.bmx and give us a like! Then upload a photo of your bike and the serial number. We'll take a look and try to help you out.

Thanks for reading. If you liked this post, sign up to the blog via email at the bottom of the page and get every post direct to your inbox. For more information on this BMX and more, you canLIKE my Facebook page, to receive regular updates in your feed, visit there-rides websiteor see the rebuilt and restored rides and parts for sale on our eBay store. For more images of all our re-rides in progress follow us on Instagram.

Your guide to old Mongoose serial numbers. Find our what year your BMX was built and sold and date mid school and new-school bikes made between the mid 90’s to mid 2000’s. The guide covers many serial numbers but not all. There were many different factories making Mongoose BMX bikes and all had different serial number codes.

Mongoose serial number information has never really been properly documented, possibly lost as the company changed hands and moved production. However, there are a few BMX restorers who have painstakingly attempted to decipher these multi-digit mysteries.

A big part of buying, rebuilding and restoring old BMX bikes, is knowing exactly how old they are. When I started looking into finding out how to read Mongoose serial numbers I found plenty of information on Mongoose BMX bikes made in the 80’s and early nineties through google and BMX forums. The problem was there was no information helping to date Mongoose BMX bikes built from 2000 onwards. It seemed nobody figured out how to read the serial numbers.

Older Mongoose bikes made through the 1980’s had pretty easy serial numbers. Generally the year and month of build was stamped as the first part of the serial number. For example my 1986 Mongoose Expert has a serial number M6EG0652. The first number (6) relates to the year – 1986. The next letter relates to the month (E) is May based on the convention January (A), February (B), March (C), April (D), May (E), June (F), July (G), August (H), September (I), October (J), November (K), December (L). It is assumed that the G0652 is the production number. There were a few variations on this type of serial number, but usually they were pretty easy to work out.

There are much more difficulties when looking at Mongoose serial numbers through the 1990’s and 2000’s. I spent quite a bit of time looking into these numbers on a few of my bikes as well as checking against other Mongoose BMX owners to see if my serial number crack was right. It seems to hold up and here it is.

Mongoose serial numbers are usually found stamped on the bottom of the bottom bracket. This is not always the case and there will be some bikes that do not fit into this formula.

Mid-school Mongoose BMX bikes built through most of the 90’s have a serial number that begins with 4 letters. The 3rd letter corresponds to the year of manufacture.

A B C D E F G H I
91 92 93 94 95 96 97 98 99

The 4th letter indicates the Month

Mongoose Bike Serial Decoder Online

A B C D E F G H I J K L
Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec

A few serial number examples are:

HFGB00000 – 4 letters, GB are the dates. G is the year (1997), B is the month (Feb)

HFBH00000 – 4 letters, BH are the dates. B is the year (1992), H is the month (Aug)

New-school Mongoose BMX bikes built through most of the 2000’s have a serial number that begins with 5 letters. The 4th letter corresponds to the year of manufacture and follows on from the mid-school serial numbers.

J K L M N O P Q R S
00 01 02 03 04 05 06 07 08 09

A B C D E F G H I J K L
Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec

A few serial number examples are:

HAMME00000 – 5 letters, ME are the dates. M is the year (2003), E is the month (May)

SAJPJ00706 – 5 letters, PJ are the dates. P is the year (2006), J is the month (Oct)

Please note: The Mongoose serial number will give you the build date of your BMX. Frames were normally manufactured the year before being sold in bike shops. So a build date on a frame of 2003 usually means the bike was sold in stores in 2004. This is the case with the 2003 Mongoose Brawler 24 below. The Serial has a build date of 2003, the 2004/004 on the stickers indicate this was a 2004 model.

Mongoose Bike Serial Decoder

I have confirmed this Mongoose serial number crack many times against bikes that have been known to be purchased that year, bikes with distinct graphics and colours and checked them against Mongoose BMX catalogues.

Mongoose Bike Serial Numbers

If you want to know more about the Mongoose BMX you have, visit ourBMX Catalogue website. You'll find all the original catalogue info you need including original parts lists, specs, colours and photos of restored bikes.

Mongoose Bike Serial Decoder Software

There is no function for me to reply to comments left on this post.If you have a BMX and don't know what the serial number means. I might be able to help. Go to our Facebook page https://www.facebook.com/rerides.bmx and give us a like! Then upload a photo of your bike and the serial number. We'll take a look and try to help you out.

Mongoose Bike Serial Decoder Free

Thanks for reading. If you liked this post, sign up to the blog via email at the bottom of the page and get every post direct to your inbox. For more information on this BMX and more, you canLIKE my Facebook page, to receive regular updates in your feed, visit there-rides websiteor see the rebuilt and restored rides and parts for sale on our eBay store. For more images of all our re-rides in progress follow us on Instagram.