To aid familiarisation and safety, a fundamental decision
was made to keep the existing system (pedal-drive and
mechanical brakes) de-coupled from the retro-fitted system
(electric propulsion and regenerative braking): the rear wheel
remains driven by the pedals and is mechanically braked by
the left-side brake lever, whilst the front wheel is motorised
and regenerative braking is actuated via the right-side brake
lever.