Super lightweight Brompton

world's lightest brompton

Bromptons have become the go-to folder for rail commuters, but you’ll be lucky to spot this one-of-kind custom superlight version by Derek Cranage.

Brompton’s range-topping S1E-X is a claimed 9.3 kg, but a host of bespoke carbon parts has reduced the weight of Derek’s bike to only 7.1 kg making it arguably the world’s lightest folding bicycle.

Superlight Brompton

Derek has form when it comes to beating Brompton at their own game. When we covered news of the Tern Elektron and eagerly awaited Brompton electric folding bicycles, he wrote to us about two bikes he had recently built.

To my mind, Tern have lost out; both ours fold considerably smaller than the Elektron.

One is a highly modified Brompton, which folds in the same way as the standard version but is 1 cm wider. It has v brakes and an eight-speed hub gear. It weighs 14.9 kg and the battery takes it 25 miles with an output about twice that of the Tern Elektron.

The second bike  is another eight-speed hub gear with v brakes, the same electric drive and battery as our Brompton, and a folded size of 73 x 56 x 34 cm; a bit larger than the Brompton, but considerably smaller than the Tern.  It weighs a more at 17.3 kg, but considering the eight-speed hub gear, it is light.

Both bikes have the motor in the front wheel, the battery goes in a Brompton bag at the front, and with a small amount of pedalling will go 25 miles.

You can see examples of the type of electric motor kits fitted to both bikes at

Brompton electric folding bicycle

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  1. George W


    Very interesting but, in my browser at least, the photos didn’t stay still long enough for me to appreciate the details.

  2. Michael Davis


    Ditto – pictures moving over too quickly!

  3. MARK


    Try taking a screen shot of each photo as they pass?

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