Grin: Electric Brompton Conversion Kit


Do you already have a Brompton for your daily commute and feel like adding a little magic? Well, Grin Technologies’ Brompton Conversion Kit may be just the thing! It has been developed to retain all the quick folding goodness you chose your bicycle for in the first place, whilst multiplying the effort you put in so you can get a whole lot more out of it.

Your current front wheel makes way for a new one which includes a 250W motor in the hub, then the electronics follow your existing cables along the frame. These connect the motor to the controller (the ‘brains’) above the front wheel, onto the screen on the handlebars, the sensors on the cranks and the battery in your bag – which can also be on your handlebars, or tucked under your seat in a saddlebag.

Everything you need to get rolling is in the kit, except the battery. This is because some commuters spend more time carrying than riding and vice-versa. We recommend choosing a combination of Grin’s LiGo Battery packs to fine-tune your bike for 40% more than the journey you intend to do each day, so you have the optimal balance between what you can both carry and ride – with a little in reserve.

There are a whole host of different combinations available which are likely to void the warranty which Brompton offer with your bicycle, however they are sold ‘as-is’ and are 100% street legal.

Please note that whilst a cadence sensor can slot onto your bike (providing an installation without any permanent modifications), a torque sensor requires a hole to be drilled under the bottom bracket for the cable. Both are optional: after-market kits can be operated entirely by a throttle if you prefer.

Kit Contains:

Front Direct Drive Hub Motor in 16″ ETRTO 349 Rim: MSAW20F16
20A Controller and Fork Mounting Bracket: C4820
Display Option: V3 Cycle Analyst, CA3-DP
Pedal Sensor: PAS 24P
Throttle: T-Lever
Torque Arms: Torque Arm 8mm
Tidy Wiring Kit: Wire Route Kit

Batteries not included:

Configure your battery here. We recommend Grin’s Cycle Satiator as your charger too.


Manufacturer: Crystalyte
Rim Brake Compatible: Yes
Disk Brake Compatible: No
Regenerative Braking: Yes (with additional lever kit, sold separately!)
Motor Type: Direct Drive
Motor Power Configuration: 250W



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