What is the drag level of the various ebike motor systems?

[Micmav]

I did some quick research but could not find the answer. What is the amount of drag that the various motor systems introduce to the drivetrain when the motor is off?

Surely, some euro scientists would have measured by now.

As far as I know,

Shimano - almost none since clutch disengages motor
Yamaha - none since clutch too?
Bosch - a lot since draggy and tiny chainring
Brose - quite a bit.
Fazua - none since on a one way gear?

I don't know, is it 2 watts or 20 watts. It seems to be noticeable not only when the motor is turned off but when assist shuts off at 20mph. Very hard to pedal at 21 or 22mph.

I had the same problem with my Carrera vengeance. I cut the black wire between the torque sensor and the controller then it pedeled like a normal bike, so my solution was to place a switch to the cut wires and run it up to the handlebar where I affixed it with a bit of epoxy glue, after that I would just switch it off when I wanted to ride it without the power on. I hope you find this helpful and happy riding in the future.

 

[Micmav]

I forgot to mention that the drag still happens when the lcd indicates off or is switched off.... Hence why I had to put in the switch but this worked for me.

 

[HighPockets]

So glad that others are discovering the historic mistakes made because motors were designed by motor people, not pedal people, those being: 1. No clutch or freewheel on the motor to detach it while just pedaling. 2. Disabling the throttle while pedaling.

Be aware when testing that just hanging weights on the pedal will not catch the drag. Viscous losses like moving grease increase as the square of speed, and electromagnetic hysteresis losses from the armature only happen in motion. Take the chain off and try to spin the cranks forward faster and you will discover what I mean.

My solution for the drag with a dead battery was to screw on a 24t chainring so I could kick the chain onto it and get home up the hill with my damaged knee on one leg and a prayer. An angel was over my shoulder there. The manufacturer had some hidden genius that knew what I needed to put holes in the right place for the chainring. Some ancient TA Cyclotouriste bolts and spacers and less than a buck in washers under the screw heads worked fine.

 

[Hoggdoc]

I test rode a Levo Expert today and something seemed a little off; it was the power. Much less resistance without the motor than my Yamaha PW-SE bike. I also like the instant engagement of the motor; it must use a roller or sprag clutch. You’re lucky to own one.

I didn’t really notice the extra torque of the motor; probably because it’s a 29er and I have a smaller chainring on my bike. But wow; even on parking lot ride with a short excursion into a rocky catch basin and back out this bike blows me away; I want one .

If you are talking about the Turbo Levo Expert I'd have to say for $11,000.00 it ought to do more than blow you away. Some of these prices are just crazy, these are bikes not Motorcycles or cars.