Skarper: The Revolutionary E-Bike System That Fits in Your Hand

Skarper, a company founded in 2020 based in North London, is reimagining the e-bike. Once you attach the Skarper disc brake rotor system to any standard bicycle, you can transform it into an e-bike in seconds. Then simply remove the system to return to a traditional bike. This allows you to have all of the convenience of an e-bike without giving up or switching your existing bike. And the disc brake rotor is small enough to fit in the palm of your hand. Skarper’s Camden office has over 20 people working there across mechanical, electrical engineering, and industrial design.

Co-founder Dr. Alastair Darwood, a doctor with a background in medical device engineering, wanted an e-bike without the bulk and expense. Finding existing conversion kits too heavy, he decided to create something more convenient. He wanted the challenge of inventing something that people wanted to use, not a medical device they needed to use.

There are two main methods of powering an e-bike: using hub motors (in wheels) or mid-drive (at pedal cranks). Skarper has developed a third method with the disc drive. This gives customers the option to switch between an e-bike and a normal bike without modifying the underlying bicycle, providing freedom to consumers and manufacturers. But packing the motor, gearbox, battery, and electronics of an e-bike into an easily detachable handheld unit was a huge engineering challenge. There were no components existing on the market that were small enough to make this work. This meant that Skarper spent their first years designing their own speed controller, electronic boards, and battery management system, creating one of the smallest, most powerful speed controllers available.

Skarper addresses some of the main environmental issues involved in the e-bike industry. Each Skarper sold means one less heavy e-bike manufactured, plus it gives unused bicycles a new life as e-bikes. Its compact size means that shipping and posting parts for warranty repairs have a much lower carbon footprint. And by separating electrical components from the bicycle, it extends the underlying bike’s lifespan.

Skarper partnered with Red Bull Advanced Technologies, bringing Formula One engineering to consumer cycling. Red Bull's expertise helped solve power and torque density in a small space. Their testing ensures it survives F1 standards, British winters, and Alpine climbs! The Test Lab at Skarper’s North London office has custom rigs designed to stress test units to destruction, running at maximum power (430 mechanical watts) for over 2,000 kilometers to find the limits of the engineering. A waterproof chamber simulates torrential rain to see how it will cope. While early rotors failed after 20 minutes, with Red Bull's support, current designs withstand weeks of the most extreme testing.

The company’s bluetooth app offers eco, cruise, or turbo modes. Turbo works like a motorbike, allowing the rider to lay off pedaling. Eco mode dynamically adjusts power based on incline and cadence. Backpedal three times to pause or reactivate the motor. The system caps at 25 km/h with automatic clutch disengagement above that speed. Customers frequently report how smooth the onset and offset of power is, and how responsive the system is.