Two drive debutants were compared with the competition in this test field: the brand new mid-motor from Brose and the BionX D-Series rear hub motor, which has been installed on Wheeler bikes since 2014. The BionX was particularly surprising. The high efficiency that the external rotor unit achieves from its large diameter greatly reduces energy consumption. Although the average speed uphill is lower than that of mid-drive motors, the BionX passed the range test with flying colours and only got a little warm to the touch. If the speed drops below 10 km/h on the mountain, however, it shows typical hub motor behaviour: Its performance decreases noticeably. Brose's mid-motor impresses with its smooth running and presence. The drive responds sensitively and with sufficient power to the pedal stroke, engages promptly and does not lag. However, it does not master longer climbs as confidently as its competitors from Bosch, Yamaha or Impulse. In the hill climb test, it noticeably reduced its power output for the first time after around 550 metres in altitude. Short cool-down breaks brought it back up to speed for a further 350 metres in altitude, until the battery was empty after 1,260 metres in altitude.
The Panasonic PCT hub motor on the KTM is ambivalent: at speeds above 12 km/h it pushes at an above-average rate, below that it seems rather tired. We had to end the test on a longer, steeper ramp on the test course because the speed was permanently below 5 km/h. The SyncDrive on the Giant Talon made a positive impression on us. Alongside the BionX-D-Series, it is the only rear hub motor that passed our uphill range test without failing or cooling down.
YAMAHA
The steering is very balanced. You only feel the motor assistance switch on or off slightly and gear changes are smooth. The range on hills suffers somewhat from the high energy consumption of the drive. Unfortunately, epic tours are not possible.
CONCLUSION
Thanks to the good set-up, the Yamaha motor is very pleasant to ride - it is one of our favourite drives. Only a little more range would be desirable.
BROSE
The Brose starts up smoothly and the cut-off is very unobtrusive. There is no gearshift sensor, but you won't miss it if the gears are well adjusted. The compact design looks stylish and can be combined with a standard chainring. There is a drop in performance on long uphill climbs.
CONCLUSION
If the Brose were more stable on long, steep climbs, it would be a real alternative to the Bosch. Its support is a little gentler, for full power you have to pedal a little harder.
PANASONIC PCT
An internal gearbox in the Panasonic PCT is intended to eliminate the disadvantage of the hub motor concept - overheating at high power and low speed. In terms of motor temperature, this works. However, this comes at the cost of a significant reduction in performance at low speeds on steep climbs.
CONCLUSION
A real power pack for less steep and long climbs. Panasonic riders need good legs for long, steep climbs.
BOSCH PERFORMANCE
Bosch has set standards for mid-mounted motors that are still valid today. The control system works well. There are no problems when shifting gears. You can clearly feel the shifting on and off, but it is not annoying. The biggest difference to the competition is the high average uphill speed of the Bosch drive.
CONCLUSION
The concept is not new; in recent years, Bosch engineers have only improved the details of the tried and tested motors. Nevertheless, Bosch is still at the forefront.
BIONX D-SERIES
With the D-Series, BionX has significantly upgraded the hub motor concept. The drive no longer overheats and energy consumption is significantly lower. This is good for the overall weight, as the battery can now be somewhat smaller and therefore lighter. However, there is only plenty of power and thrust at speeds of 10 km/h and above.
CONCLUSION
A sturdy hub motor that impresses with low energy consumption - roughly on a par with mid-drive motors.
GIANT SYNCDRIVE
Although the power of the Giant SyncDrive is rather moderate overall, it provides noticeably more support from around 5 km/h than its hub motor competitors. The range on climbs is also impressive. Slowly, but without failure, the drive pushes upwards until the battery is empty.
CONCLUSION
Perhaps the best hub motor for sporty MTBs: usable power even at low speeds and little tendency to overheat. Disadvantage: high energy consumption.
IMPULSE 2.0
The Impulse 2.0 still has room for improvement in terms of engine management. It lags for a long time, and when shifting uphill, the power is lost for so long that a gear change is immediately necessary. The maximum power is slightly lower than that of other mid-engines.
CONCLUSION
The lower power of the Impulse 2.0 is hardly noticeable in a negative way. However, the switch-off behaviour could be better and the switching interruption should definitely be shorter.
