The drive train is the centerpiece of the e-bike and is subjected to significant loads. To ensure long-lasting and safe enjoyment of the bike, a high-quality motor is needed.

Riders who spend a lot of money on a modern e-bike expect a quality product to enjoy for many years to come. Unfortunately, not all motorized bicycles live up to these high expectations. A new insurance survey shows that almost a quarter of all damage to e-bikes results from technical problems caused by the motor and battery. Reliability and durability are therefore the key criteria when choosing the drive train.

Quality from medical technology and spaceflight

In the development of the BIKEDRIVE AIR, maxon has the benefit of 60 years of experience in building efficient, robust, and maintenance-free motors. “Our technology has been designed to pack a lot of power into a small space,” says Stefan Müller, head of Mobility Solutions at maxon. “To achieve this, our motors have to be precise and absolutely reliable.” This applies in particular in the case of medical technology such as pacemakers, or in the case of motors for spaceflight – locations where it is hardly possible to perform any maintenance later. For Swiss drive manufacturer maxon, quality control is therefore a top priority – and of course e-bikes are no exception.

“Quality starts with the design,” says Stefan Müller. Which loads will occur, which forces have to be considered? The drive train, as the centerpiece of any e-bike, is particularly vulnerable as a mid-mounted motor and for off-road use. “Since our components are within the frame, they are better protected against impact and water,” says Stefan Müller. On most e-bikes, the seal on the bottom bracket shaft is their Achilles’ heel, as the seal cannot be made entirely water-tight. On electric mountain bikes in particular, strong forces act on the drive on steep inclines – plus all components get significantly more soiled.

Bottom bracket as Achilles’ heel

“With the BIKEDRIVE AIR, we have found a solution that works as well for a racing bike as it does for a mountain bike,” says Stefan Müller. “Due to the small dimensions of the motor, the bottom bracket remains very compact.” Due to a short Q-factor from 155 millimeters, in other words a short distance to the pedals, it has less surface for damaging factors to act upon and it additionally protects the hips of the riders against lateral stress.

“Our drive systems are as tough as they come.”

Stefan Müller, Head of Mobility Solutions at maxon

Another point to consider was the torque. High support levels combined with large gears require bigger components and subject the drive train to severe strain when gears are shifted rapidly. Especially if the motor is running continuously. The patented freewheel technology of the BIKEDRIVE AIR therefore has been designed specifically with sporty cyclists in mind and only activates the drive when it is really needed. This reduces the strain on the components.

Sensitive support

Freewheeling without support does not cause friction, which means the rider feels no resistance. “The activation and deactivation of the support feels very natural,” says Stefan Müller. “The torque sensor detects stronger pressure on the pedals and the drive immediately converts it into more power.” The integrated electronics and sensors enable sensitive support in all driving situations – this benefits both the components and the rider’s joints.

Tested inside out

The products in maxon’s portfolio, like those mounted in the Mars robot of NASA, have been designed to reliably perform their tasks under extremely difficult conditions. In the quality check, maxon also tests the e-bike components on all levels; both the motor and the entire drive unit are subjected to a wide variety of strains. Finally, the complete e-bikes, such as those resulting from the cooperation with Cipollini or Transalpes, are are examined at the Lucerne University of Applied Sciences and Arts, where the drive train in the finished product is tested inside out. Outside of laboratory conditions, professional cyclists such as Alessandra Keller or Ralph Näf put the maxon drive systems through their paces – and they are not disappointed.

Individual configuration and care

In the “maxon Rider” app, the support levels and preset riding profiles can be individually adapted to the rider. This not only optimizes the interaction of muscle power and electrical support, but also reduces wear to a minimum. After falls or impacts, qualified mechanics perform diagnostics by means of the Service app and can order spare parts if necessary. Thus there is no maintenance for the end customer with the BIKEDRIVE AIR, apart from having to charge the battery. “Our drive systems are as tough as they come,” says Stefan Müller. “Nevertheless, riders should not just assume their bikes can handle everything.” Loving your e-bike also means giving it regular care.

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