Automatic gearbox and motor combinations
From a bike design perspective, there have been a few innovations within the past decade that have single- handedly made life infinitely easier. One notable example is the gradual redundancy of the front derailleur, as parts makers have got to grips with condensing a wider range of gearing into a single cassette; we’re now at the point where 1x 13 cassettes exist from manufacturers like Campagnolo with its new Ekar groupset and Rotor Components. How does that benefit beyond a little weight- shaving and reduction of moving parts, you ask? Well, from a frame designer’s perspective, not having to factor in a front derailleur has allowed for geometry adjustments that were previously unthinkable, but which can offer great benefit in terms of the way a bike rides.
For the electric bike frame designer factoring in a series of gears, motors, batteries, internal cable routing and plenty more, it means there’s now another battle underway – to place components without compromising that hard-fought ride feel. In turn, the key demand on motor makers has been to create an ever- smaller package. Yamaha, for example, reduced the size of its latest generation PW-X3 motor by 20% over the prior X2.
Better still from a manufacturer’s perspective is the idea of the gearing and the motor sitting within the same body, giving valuable real estate all along the chainstay with which to innovate. For the consumer, having both encased in a sealed unit is immensely valuable in terms of maintenance, particularly with the UK weather being prone to wearing down moving parts.
One start- up bringing this idea forward with a working prototype is Scotland’s Intra- Drive which has succeeded in housing an eight- speed, 430% range gearbox alongside a motor capable of delivering 100+Nm of torque to the rear wheel. At under 5kg for the entire unit we would expect investors to take an interest as the firm seeks to crowdfund the system late in 2021.
Valeo is another brand with working prototypes. Developed alongside French gearing expert Effigear, its system comprises a 48V, 130Nm electric motor and seven-speed automatic adaptive gearbox in one housing. Gear shifting happens without any need for rider input, with a seamless transition that glides through the range in milliseconds.
“Having the motor and gearing in a sealed unit is immensely valuable in terms of maintenance”