Bosch Performance CX Motor causing resistance

[Lewymunga]

I have a Cube Stereo Hybrid with the Bosch Performance CX motor. I have a few concerns with the amount of resistance in certain modes.
In turbo mode, when I stop pedalling it feels like the bike is slowing down very quickly, almost like holding the brakes lightly?
When it hits the speed limit going downhill the amount of resistance to pedalling is high? This makes it hard to pedal downhill.
Finally if I turn the motor off, my understanding is a clutch should be engaged and it should be easy to pedal. It is the opposite. It is difficult to pedal???
Any thoughts for someone new to ebikes?
Thank you all,
Lewis

 

[Greg Watts]

I have a Cube Stereo Hybrid with the Bosch Performance CX motor. I have a few concerns with the amount of resistance in certain modes. In turbo mode, when I stop pedalling it feels like the bike is slowing down very quickly, almost like holding the brakes lightly? When it hits the speed limit going ...

Welcome to the slightly bewildering world of eMTBs, @Lewymunga. All three of those things you're describing are completely normal behaviour for the Bosch CX system, not faults.

The deceleration when you stop pedalling in Turbo is the motor cutting assist abruptly. At higher assist levels the transition from "motor helping" to "motor doing nothing" is quite sharp, and on a 21kg+ bike that's noticeable. Try dropping to eMTB mode, which is adaptive and gives a smoother cut-off.

The resistance at the speed limit is a known characteristic of Bosch's system. When you hit 25km/h the motor cuts out but the motor's internal mechanism creates drag as the drivetrain spins through it. This is what people mean when they say eMTBs feel "heavy" above the limit. Going downhill past 25km/h you're fighting that drag on every pedal stroke. It's physics, not a fault.

The resistance when the motor is switched off is the same issue, just more pronounced. There is no true "neutral" freewheel on the Bosch CX when off. The Gen 5 is better than previous generations in this regard, but it's still noticeable compared to an analogue bike. The clutch mechanism you've read about helps but doesn't eliminate it entirely.

Short version: your bike isn't broken. This is just what Bosch-powered eMTBs do, and you get used to it. Most riders leave it in eMTB mode for trail riding and only touch Turbo for brutal climbs.