Skarper disk brake propulsion system turns any bike electric
Breaking cover today for the first time with Olympian Chris Hoy’s backing is a new retrofit eBike conversion kit, dubbed Skarper, that utilises a supplied disc brake in a bike’s rear wheel to provide propulsion.
A unique concept in retrofit drives, which are typically reliant on hub drives without utilising the braking system, the chainstay mounted system is to ship its first units in 2023 and cost around £1,000. The product is described as a ‘click on, click off’ package that can be fitted to any bike with disc brakes and a promotional video (seen below) seems to demonstrate as much, with users hitting a quick release to remove the system in seconds.
The Skarper unit’s integrated lithium ion cells fully charge in under 2.5 hours and apparently have a range of up to 60km thereafter, plus 50Nm of torque to help the rider along. With a suite of sensors and control algorithms, the motor intelligently responds to the terrain and provides instant power as needed. Those algorithms are able to detect rider input, terrain incline change and the need for input from standstill.
For those questioning the concept and its suitability to be fitted to a bike where testing will not have factored in a retrofit drive, Skarper outlines that “the disk behaves exactly as a normal disk without any compromise on performance or function.”
The brushless hub drive is in fact built to sit inside a special disc of Skarper’s design and we’re told that there will be iterations of the design for city bikes, road bikes and even mountain bikes. What’s more, the system will be aligned to the speed restrictions of the country within which it is sold, up to a maximum of 32km/h.
Dr. Alastair Darwood is the creator and co-founder. His prior innovations have broken ground in the medical world; most notably he developed a novel emergency ventilators selected by the Cabinet Office for rapid production and worked with Red Bull Advanced Technologies to develop the device.
“At Skarper, we live and breathe innovation and this is just the beginning of our product development”, says Dr. Alastair Darwood. “The Skarper system is fully enclosed and wire free, seamlessly integrating into your bicycle via its DiskDrive technology. It is an ultralight, clip-on motor technology, transforming any bike into an eBike with no modification required to the frame or wheels, and without compromise on performance. We are also very excited to be working with Red Bull Advanced Technologies on an off-road version, news of which will be released later this year.”
The system will be shown to the public for the first time at the National Cycling Show at the NEC in Birmingham on the 18th June.
Other retrofit systems on the market include Pendix, Swytch and the Copenhagen Wheel.
