Know your Brompton line
Know your Brompton: identify your model, line and year
Not sure whether you ride an A Line, C Line, P Line or T Line — or what your model code and handlebar type are? Use the tools below to find out how old your Brompton is from its serial number, and to identify its exact configuration. A full reference guide follows underneath.
How old is my Brompton? Serial number checker
Enter your 10-digit serial number to find the month and year it was made.
Where do I find my serial number?
It's a 10-digit number on a small curved sticker on the rear of the seat tube (the upright tube the saddle slides into). The first four digits are the year and month — e.g. 1903… means March 2019.
Not the same as the frame number: the 6-digit number stamped into the metal near the bottom bracket is the frame number and can't be dated directly. If your serial sticker is faded or missing, Brompton can recover it from the frame number.
What model Brompton do I have? Identify it in 3 steps
Answer three quick questions about what you can see on the bike.
Which handlebar does your bike have?
How to read a Brompton model code
Most Bromptons have a model code made of three parts: handlebar type, number of gears, and a trim suffix. For example, M6L means an M-type handlebar, 6 gears, and mudguards. The first letter is always the handlebar; the number is the gear count; the final letter describes what's fitted (L for mudguards, R for a rear rack, E for a bare frame with neither).
Brompton handlebar types explained
The handlebar is the most defining feature of how a Brompton rides, and the first letter of every model code.
S type — sporty
The lowest and most forward of the handlebars, giving a sporty, aerodynamic riding position. It's the lightest option and is favoured by riders coming from road bikes. Note that only the S-Bag front bag fits this handlebar.
M type — medium
The classic, most popular Brompton handlebar. It offers a comfortable, moderately upright position with excellent control — the all-round choice for most riders.
H type — high
The most upright position. The H type uses the same handlebar as the M type but on a longer stem, sitting roughly 6 cm higher. Because the bar itself is identical to the M, the two are easily confused — the giveaway is about 2 cm of extra stem under the hinge.
P type — multi-position
A butterfly-shaped touring handlebar offering several hand positions, designed for longer rides. It was discontinued around 2019, so it marks an older or specialist bike (mainly older C Line models).
Brompton lines and how to tell them apart
Brompton's current range is organised into lines. Check the gearing, frame material and any branding to identify yours.
| Line | Typical gearing | Frame material |
|---|---|---|
| A Line | 3-speed | Steel |
| C Line | 2, 3 or 6-speed | Steel |
| P Line | 4-speed (lightweight) | Steel + titanium |
| T Line | 4-speed (premium) | Primarily titanium |
| Electric Line | 2 or 6-speed | Steel, with motor & battery |
| G Line | Multi-speed (mixed terrain) | Steel, larger 20″ wheels |
Quick checks: look for decals, engravings or laser-etched details indicating the line; count the gears; and check whether the bike has a battery and hub motor (Electric Line). If you're still unsure, contact Brompton support with your serial number for confirmation.
The 2017 handlebar redesign
In 2017 Brompton subtly reshaped the M and H handlebars to make room for the integrated brake/gear shifter, which also allowed a standard 130 mm grip. The bars look almost identical, but it's a real dividing line: bikes made before and after 2017 can differ in grip and shifter fitment. The serial-number date above tells you which side of that change your bike falls on.
Bromptonic is an independent retailer of aftermarket Brompton accessories and is not affiliated with Brompton Ltd. The build date is calculated from the standard Brompton serial-number format (year and month in the first four digits) and is a guide. Your serial number encodes the manufacturing date only — your model and handlebar type are identified from the features visible on the bike.