It only arrived at the end of 2025 - the new Brompton Electric e-Motiq system (the one with the motor in the rear wheel) and of course the questions about what can be upgraded / changed are in everyones mind
So, what can you change / upgrade - and what can't be changed - these are some of the questions we have had ... so far
Yes 👍
Most standard parts such as pedals / saddle / grips can easily be changed
Standard Brompton specific parts such as the seatpost
Yes .... but
Adding a roller rack to a C Line / P Line / T Line e-Motiq
You can easily add an advance roller rack if you specified your bike without one
BUT you will need to replace the rear light as the cable needs to be longer (30cm longer) when used with a rack
The cable on the non-rack version just won't stretch far enough and unfortunately the cable is not available on it's own
Not Yet - hold your horses 🐎
Changing the chainring size - P Line / T Line e-Motiq
The e-Motique system uses a square taper bottom bracket (torque sensing)
The P Line and T Line ranges come equipped with a new lightweight crankset (the C Line uses the same crankset as the G Line electric and the C Line / P Line manual bikes)
This means that the chainring size can't (currently) be changed as there are no (Brompton) chainrings available - yet
You could change to a standard crankset if you want to change the gearing and don't want to wait
Maybe 🤞
Lights?
We "think" that the Brompton e-Motiq system uses proprietary connections for the lights
Rear Light
The lighting cable that comes with the bike as standard has a double spade connector on the end the connects to the light (the standard rear light is the Busch and Muller 2C) and a Brompton specific connector on the end which plugs into the control unit
So you could change the rear light if:
1/ it uses the same spade connectors
2/ you use the existing lighting cable
3/ the light is a rack mount with 50mm spacing between the bolts
Front Light
We still need to check this
Handlebars?
The e-Motiq P Line uses a new alloy handlebar stem - which in turn uses a new handlebar with a (quite standard) 31.8mm diameter
It comes offered as a mid-rise or high-rise version
In theory you could put the T Line straight bars to give a lower / more sporty riding position (and save some weight)
Status: We have yet to try this but we are pretty sure it will work
Headset
So, you'd like to fit (for example) a Chris King headset
The e-Motiq frames have a wider head-tube into which the headset fits - so it's no longer the traditional 1 1/8 inch one used on the older bikes
The C Line (which still has a steel stem) uses an adapter / reducer to make the stem work with the new larger head-tube
The P Line uses a new headset - we don't know the specification yet
Status: Brompton now use a proprietary headset size - in the future we guess someone will make an adapter (e.g. Brommie Plus) but until then you are stuck with one supplied by Brompton
No 👎
Bottom bracket
For example fitting a Shimano square taper bottom bracket or putting in a Schlumph drive
As the bottom bracket features a torque sensor and is an integral part of the system - it can't be changed
Superlight crankset from T Line
The Brompton T Line superlight crankset (used on the manual T Line) uses a (made by FSA) external bottom bracket (as opposed to a square taper bottom bracket)
Because the e-Motiq uses a specific torque sensing bottom bracket with a square taper interface - the superlight crankset can't be fitted
On the T Line e-Motiq, Brompton get around this with a new crankset (with a square taper interface) which is quite different to the one used on the manual T Line
Internal tool kit
There are three versions of the internal tool kit:
- P Line / C Line (older model Brompton bikes - though not the short wheelbase version)
- G Line
- T Line (introduced in spring 2026)
The internal tool kit (originally introduced for the C Line / P Line) won't fit the e-Motiq range of Brompton folding bikes as the wires are internally routed (running through the frame) which means that the tool kit won't fit (it will fit on the original Brompton C Line / P Line electric range of bikes)
Tool pouch
The triangular tool pouch (originally introduces with the P Line CHPT3 special edition) and finally launched in 2025 fits in the triangle at the rear of the main frame
There are two versions of the tool pouch:
- C Line / P Line / T Line version (and older models with 16 inch wheels)
- G Line
The pouch won't fit on the e-Motiq range of bikes during to the wires running through this rear triangle space
Front carrier block
The front carrier block (for carrying luggage) for the Brompton e-Motiq us part of the electric system - so you can't put on a standard carrier block or one of the new colour touchpoint forged carrier blocks
Older bag frames
The frame design (most specifically the interface between the front carrier block and the frame where the battery attaches) has changed
This means that older Greenway or adapter frames can't be used on the e-Motiq system bikes
If you want to use an older Brompton electric bag on an e-Motiq bike you will need a new frame
We made the below video showing the differences and compatibility between the batteries (we were talking about the G Line as the e-Motiq series hadn't been launched by then)
Older (BMZ) batteries
The older (BMZ) batteries are different to the newer (Greenway batteries) and won't work on the new e-Motiq bikes, in fact they may damage the system
(Please see the above video for more information)