21% increase in power
The EP8 drive unit (DU-EP800) provides 85Nm of torque, a 21% increase in power over its predecessor, the Shimano Step E8000. Thanks to the magnesium drive units, the system weighs only 2.6kg, a 10% weight reduction compared with the E8000. Shimano also reduced the friction that comes with a pedal rotation, noticeable when operating the system without power by more than a third.
This friction reduction creates improved battery efficiency when the motor is active, or a smoother ride when pedaling without support. For example, when the motor is switched off or when riding above 25 km/h. Together with the friction-reduction is an improved clutch mechanism which provides a smoother cut-off when pedaling above 25km/h. Despite the increased torque, Shimano claims lower noise levels.
According to Shimano, the smaller magnesium drive unit shell features improved heat-conducting properties with redesigned internals, like optimised gear structure and new EW-SD300 wires. These all aid cooling and improve performance when operating at maximum torque on long, steep climbs. The drive unit case is also shaped more in line with the smooth lines and angles of bike frames which improves ground clearance and, together with internal batteries, makes Shimano EP8-equipped bikes sleeker.