Know Your Brompton
Guide
Know Your Brompton
Every Brompton folds the same way. But not every Brompton is the same bike. Before you buy an accessory, it helps to know which line you ride — so you get the right fit, the right weight, the right match.
This guide helps you identify your model in under two minutes.
How to identify your model
01
Look for labels or engravings
Most Bromptons have decals, engravings, or laser-etched markings on the frame indicating the line. Look near the head tube or on the frame near the bottom bracket.
02
Count the gears
- 3 speeds — likely A Line
- 2, 6 or 12 speeds — likely C Line
- 4 speeds, lightweight — likely P Line or T Line
- Motor on the rear wheel — Electric Line
- Larger wheels, disc brakes — G Line
03
Check the frame material
- Steel only — A Line, C Line or Electric
- Steel + titanium parts — P Line
- Primarily titanium — T Line
- Steel, updated geometry — G Line
04
Weigh it (roughly)
- ~11–12 kg — A Line or C Line
- ~9.5–10 kg — P Line
- ~7.5–8 kg — T Line
- ~14–17 kg — Electric Line
- ~14.5 kg — G Line
The Brompton lines
A Line
Entry level
The most accessible Brompton. One size, one colour, one spec. No mudguards or bag mount as standard — but fully compatible with C Line accessories.
C Line
Most popular
The classic. Versatile, well-rounded, and the bike most Foldrio customers ride.
P Line
Performance
Lighter, faster, more refined. For riders who want performance without going full titanium.
T Line
Ultra-light flagship
The lightest Brompton ever made. Titanium frame, carbon components. Nothing is compromised.
Electric
Assisted riding
Available across multiple lines. Rear hub motor, detachable battery. Effortless on hills and longer commutes.
G Line
Go anywhere
Bigger 20" wheels, disc brakes, gravel-capable tyres. Designed for mixed terrain and comfort. Also available electric.
Reading your serial number
Every Brompton made from late 2001 onwards has a 10-digit serial number. It tells you exactly when your bike was built — and it's the number you'll need if you ever need to register your warranty, report it stolen, or contact Brompton support.
Where to find it
Look on the back of the seat tube — the vertical tube the saddle slides into. On bikes made after 2015 it's engraved on a small metal badge. On older bikes it was a sticker.
Frame number vs serial number
These are two different things. The frame number is stamped directly into the metal of the rear hinge. The serial number is on the seat tube badge. You may need both when contacting Brompton.
Register your bike
Registering your serial number with Brompton activates your 7-year frame warranty (2-year on electrical components). Worth doing the day you get the bike.
Still not sure which model you have?
Send us a photo of your bike — front, side, and the area near the head tube — and we'll identify it for you. We know this bike well.
Get in touch →Quick comparison
| Line | Best for | Weight | Gears | Brakes |
|---|---|---|---|---|
| A Line | Budget-friendly commuting | 11.3 kg | 3-speed | Rim |
| C Line | All-round everyday use | 11.1–12.5 kg | 2, 6 or 12-speed | Rim |
| P Line | Performance & speed | ~9.65 kg | 4 or 12-speed | Rim |
| T Line | Ultra-light travel | from 7.45 kg | 1, 4 or 12-speed | Rim |
| Electric | Assisted commuting | from 14.1 kg | 4 or 12-speed | Rim / Disc |
| G Line | Comfort & mixed terrain | ~14.5 kg | 8-speed Shimano Alfine | Disc |