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Bike Serial Numbers

where to find a bike serial number

Most cyclists don’t understand the importance or use of a bike serial number until they need it! 

However, knowing your bike’s serial number is essential and can drastically increase your chances of recovering your bicycle should it be stolen. 

In this short article, I’ll cover what a bike serial number is, what a bike serial number does, how to find and read a serial number, and what to do if your bike does not have a serial number.

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    What Is a Bicycle Serial Number (Frame Number)

    A bicycle serial number often referred to as a bike frame number, is a unique sequence of numbers typically between 6 and 10 digits long.

    Almost every bike manufacturer stamps a unique frame number onto the bikes they produce[1].

    Occasionally before the serial number, there may be a couple of letters. For example, some Specialized bike serial numbers start with “WSBC”, or many Trek serial numbers begin with “WTU”.

    Every bike receives a unique code, serving as a means of identifying a single bike against those of the same model. Especially helpful for manufacturers who produce thousands of identical bicycles.

    serial number on bicycle frame on underside of bottom bracket shell
    Many old bikes with steel frames have a serial number stamped onto the frame
    sepcialized bike serial number chart on down tube
    On my Specialized bike the serial number is on a stikcer underneath the down tube
    bmc bike serial number on underside of bottom bracket
    The serial number for most BMC bikes made after 2014 can be found beneath the QR code on the underside of the bottom bracket

    Why Are Bike Serial Numbers So Important?

    Bike frame numbers are essential for many reasons. 

    Firstly, bicycle serial numbers are helpful if a bike is stolen or lost. If the original owner took a record of their serial number (which you should do!), and it was located down the line, they’d be able to prove ownership of the bicycle.

    Additionally, cyclists can register bicycle frame numbers with online bike databases, free of charge! By logging your serial number and bike details, if your bike was stolen, you can mark it on the database as stolen.

    If an unknowing buyer then searched the serial number online before purchase, they could be alerted that the bicycle is stolen property. I’ll cover this in more detail later.

    Theft isn’t the only unexpected scenario where a serial number is important. For example, manufacturers that offer a warranty can pinpoint when you purchased a bike using its serial number—allowing them to confirm if the bicycle is still covered under warranty.

    Expensive items such as phones, laptops, and automobiles (VIN) use serial numbers or identification numbers. This provides an extra level of security for supply chains and consumers.

    Where Is the Serial Number on A Bike?

    Bike serial numbers or frame numbers are usually stamped on the underside of the bottom bracket shell (see diagram).

    The bottom bracket shell is the part of the bicycle that houses the bottom bracket, connecting and allowing the crank arms to rotate.

    While this is the most common location for a bicycle serial number, some are found on different parts of your bike.

    If you cannot locate your serial number on the bottom bracket, it should be printed on one of the following areas of your bike:

    • Bottom bracket (most common)
    • Headtube
    • Headset
    • Chainstays
    • Top of crank
    • Down tube
    • Seat tube
    diagram showing where to find a bike serial number

    If you have searched all of these locations and can’t seem to locate the serial number, it may be that your bike does not have a serial number.

    Don’t panic!

    Below I explain what to do if your bike has no serial number.

    What To Do If Your Bike Doesn't Have a Serial number

    If your bike does not have a visible serial number, don’t worry! Serial numbers can be rubbed off or made illegible by years of wear. 

    If you discover that your bike lacks a serial number, there are several steps you can take to make your bike easily identifiable.

    These methods won’t reveal your old serial number, but they’ll provide an additional level of protection should your bike be stolen.

    Use one of the following methods of personalization:

    Bike Marking Kits

    Several companies provide bicycle marking kits that allow you to mark your bike with a unique number. 

    BikeRegister (a partner of BikeLockWiki) provide a marking kit that chemically etches a unique combination of letter and numbers and their website URL to your bike’s frame.

    Kits like this significantly increase the chances of your bike being returned to you if it was stolen.

    I cover more about bicycle serial number databases below.

    Seat Tube Method

    1. Write your details (full name, date of birth and mobile number) on a small piece of paper, making sure they’re easy to read. 
    2. Insert the paper into a watertight bag such as a Ziploc plastic bag, or if you can laminate the paper, this will also work.
    3. Place the waterproof bag into a lightweight carrier bag (you’ll understand why in a second!). 
    4. Remove your bike’s seatpost and push the bag holding your waterproofed details down into the seat tube.
    5. Re-insert your seatpost, and you’re good to go.

    Obviously, this method of bike identification is non-permanent. If a thief stole your bike, they might remove the plastic bag if they discovered it. The chances are, though, they won’t.

    If you were then lucky enough to come across your bike, you would have a way of proving ownership. 

    The plastic bag will also make sure the paper doesn’t rattle around inside the seat tube and will make removal less of a faff.

    Engraving Method

    This method should not be attempted by children. Before following this method remember that engraving your personal details onto your bike will decrease its resale value, 

    1. Using a sharp tool such as a screwdriver or a strong scalpel, etch your details into the paint on your bike’s bottom bracket or wherever is easiest for you.
    2. Your full name, date of birth and mobile number will be enough.
    3. The more you’re able to engrave, the better, but take care when doing so.

    While the three above methods won’t replace the original serial number, they’re several easy ways to make your bike identifiable as your property.

    How Do You Read a Bike Serial Number?

    A bicycle frame serial number is a 6-10 digit long sequence of numbers.

    The interpretation of the digits on your bike’s serial number varies based on the method of coding that each bike manufacturer uses.

    Digits of a bike frame number might state the year and month the bike was made with an ID number unique to the bike.

    Serial numbers will typically also specify the location where a bike was manufactured, along with its batch number.

    Alternatively, some manufacturers use a completely random combination of numbers that are logged in their database. Then, when searched for, the relevant information of the bike in question is pulled up. 

    If you want to know what your frame number means, a serial number decoder or lookup service can give you more insight. Search the brand of bike you have followed by “serial number lookup”.

    Register Your Bike Serial Number

    As I’ve already covered, several online bicycle databases allow you to log your bicycle frame number, along with other details such as frame size, colour and sometimes you’re also able to upload images of your bike. 

    By registering your details, documented proof will exist verifying that the bike with this serial number belongs to you[3]. Keep a hard copy of your serial number as well, and keep it somewhere safe.

    There are several online bike registration services available. The three best options are:

    Many police stations offer a bicycle serial number registration service to bicycle owners. 

    When police find a stolen bike, one of their first checks is to run its serial number through their databases to attempt to locate an owner.

    Get in touch with your local police station and see if they offer a similar service.

    That being said, one of the best databases to work with during this process is BikeRegister. BikeRegister is the United Kingdom’s leading and largest bike registration service to date.

    With BikeRegister, bike owners can verify if a second-hand bike is stolen property and even review geographical locations where bike theft commonly occurs in the world.

    How Do You Prove Ownership of a Bike? (How To Identify Your Bike)

    The most effective way to prove your ownership of your bike is by maintaining a clear record of its details. 

    After purchasing a new bike, keep hold of the receipts and make a note of its frame number. 

    Next, write your name and address on a piece of paper and holding it next to the serial number, take a photo. 

    Finally, get a selfie of you and your bike, the more evidence you have that the bike’s yours, the better!

    If your bike was then stolen and recovered, this should be more than enough to prove to authorities that you are indeed the owner.

    Do Electric Bikes Have Serial Numbers?

    As with any other type of bike on the marketplace, electric bikes utilise serial numbers.

    Serial numbers of electric bikes are found in the same location as other types of bikes. The most common location for an e-bike serial number is the underside of the bottom bracket shell, followed by the headset, top of the crank, and seat stays.

    When it comes to an electric bike’s serial number, it is essential to note that it shouldn’t be confused with a VIN (vehicle identification number).

    VINs, or vehicle identification numbers, are found on cars, mopeds, motorcycles, and other modes of transport.

    Generally, an electric bike, however, will only use a frame number.

    Is It Legal To Track Down a Stolen Bike Yourself?

    While tracking down your stolen bike by yourself is legal, I wouldn’t advise you to do so.

    Even if you pinpointed the location of the missing bike, it could be dangerous to recover it without assistance. 

    Ask for the help of your local police department or other authorities to reclaim your stolen bike.

    Working with the police or other law enforcement figures ensures that recovering the bike is done in the safest way possible.

    tracking down a stolen bike

    Police officers are trained, well-protected, and better equipped to handle thieves and robberies than a civilian.

    It simply isn’t worth confronting a suspected thief on your own. Instead, get help from the authorities.

    Bike Serial Number Search

    A range of online, searchable databases are available, allowing bike owners to look up a bicycle’s serial number.

    If you’re buying a second-hand bike, it’s a good idea to search the serial number on the databases below to make sure you’re not buying stolen property. 

    Alternatively, if you’ve already purchased a second-hand bike from a previous owner and want to confirm that the bike isn’t stolen property, you can use the bike serial number search tools below. 

    We’re a proud partner of BikeRegister,  a company that holds data on more than 1 million bikes across the United Kingdom—providing an extra level of security for registered cyclists. 

    Otherwise, if you live in the USA, the other two bike serial number search tools will serve you well!

    Bike Serial Number FAQs

    You may wonder where the frame number is on a Trek bike.

    Trek bike serial numbers are found on the underside of the bottom bracket shell, just like most bikes.

    A trek frame number will generally begin with “WTU”, followed by a sequence of 6-10 numbers.

    Older trek bikes may have their serial number in a different location, so check the serial number locator image at the top of the article.

    Specialized is one of the most popular bike brands on earth and subsequently one of the most stolen. 

    To find the serial number on a Specialized bike, you may need to examine a few different areas before locating the number.

    Most specialized bikes have serial numbers located underneath the bottom bracket, the underside of the top tube, or the underside of the downtube.

    Specialized bike serial numbers usually start with either WSBC, WUD, STT, or STE, followed by a series of 6-10 numbers.

    As the name might suggest, Giant Bikes are the largest manufacturers of bikes in the world.

    Giant bike serial numbers are typically located on the underside of the bottom bracket shell.

    Giant bike frame numbers typically start with “GM”, followed by a series of 6-10 numbers.

    If you cannot locate the serial on your Giant Bike, be sure to check the image at the top of this article for alternative locations. 

    Raleigh bikes are stamped with their unique serial numbers on the underside of the bottom bracket shell.

    Raleigh bike frame numbers often start with “W”, “WL”, or “WP”. This is then followed by a string of numbers typically 6-10 digits long.

    A bike serial number, also called a bike frame number, can be anywhere between 6 to 10 digits long.

    Additionally, some serial numbers are preceded by several letters, such as Trek bikes that use a serial number often starting with “WTU” or Giant bikes that begin with “GM”. 

    Conclusion - Bike Serial Numbers

    bike serial number decoder
    Hopefully this isn't what comes to mind anymore when you think about bike serial numbers!

    If you didn’t already know where to find a bike serial number, this article should have cleared that up for you. 

    You’ll also now understand how to prove ownership of a bike and how to register a bike serial number. 

    If by any chance you still have unanswered serial number related questions, leave me a comment below, and I’ll get back to you right away. 

    Remember, your bike’s serial number is an essential piece of information that every cyclist should keep note of.

    If you haven’t already, go ahead and register your bike serial number on one of the databases above. 

    Otherwise, make sure you’re using a good quality lock to secure your bike. 

    As always, lock it or lose it. 

    Ciao for now.

    Author of This Post:
    James Grear (Lead Editor)
    James Grear (Lead Editor)

    Understanding how devastating it is to have a bike stolen, I've researched & immersed myself in the world of bicycle security since 2013.

    I then built BikeLockWiki in 2019 to share everything I'd learned with the worldwide cycling community so that cyclists can improve their bike security skills and make informed decisions when purchasing new products and services.

    Learn More about Me & BikeLockWiki here.

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