Yamaha PW Drag

haroon01usa

New Member
I got a Haibike SDURO fullnine 5.0 about a month ago, love it. Today while driving home from work I decided to turn off the Yamaha PW engine to get a little work out. When I turned off the motor it was like I was peddling up a hill. This seems like it was something in the motor. The motor is putting a lot of resistance or drag on the cranks. Has anyone else noticed this.
 
If you are at 38 tx 40t and you have noise or drag when you turn the pedal, something goes wrong, the drag can be felt at high speeds of 38 x 11 on flat terrain.



is under warranty to be reviewed
 
I have the same thing on my s-pedelec, both when powered off and when in ECO+ and ECO mode. It is a truly massive drag also, I have the stamina to pedal max 1km on flat surfaces that way and I am a fairly strong cyclist. NO, it is not the weight of the bicycle.

Examples:
-In both ECO modes: I can freeroll practically forever without any problems but as soon as I start to pedal, the engine drags me down to a "steep hill climb" regardless of gears selected.
-Powered off: Pedaling is as if I turn the entire engine. Cycling is like having a 50kg cart behind me, uphills. I can also hear the engine being worked.

I am beginning to think something is stuck in there.
 
Feels like a flywheel in the motor that needs to spin up and then the drag is reduced after you get it going.
 
I have the same thing on my s-pedelec, both when powered off and when in ECO+ and ECO mode. It is a truly massive drag also, I have the stamina to pedal max 1km on flat surfaces that way and I am a fairly strong cyclist. NO, it is not the weight of the bicycle.

Examples:
-In both ECO modes: I can freeroll practically forever without any problems but as soon as I start to pedal, the engine drags me down to a "steep hill climb" regardless of gears selected.
-Powered off: Pedaling is as if I turn the entire engine. Cycling is like having a 50kg cart behind me, uphills. I can also hear the engine being worked.

I am beginning to think something is stuck in there.

The freewheel from the motor may have been stuck. It should be covered by the manufacturer's warranty. That's what the premium price tag is for, for the manufacturer to stand behind their products and honor the warranty related services.
 
The purpose of a pedelec is to look like a bicycle and to work even disconnected giving a good service.
 
I got a Haibike SDURO fullnine 5.0 about a month ago, love it. Today while driving home from work I decided to turn off the Yamaha PW engine to get a little work out. When I turned off the motor it was like I was peddling up a hill. This seems like it was something in the motor. The motor is putting a lot of resistance or drag on the cranks. Has anyone else noticed this.

With the power turned off and the ebike on a stand, do the pedals turn freely when cranked forward? Or is there any extra resistance as compared to a non-electric bike?
 
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With the power turned off and the ebike on a stand, do the pedals turn freely when cranked forward? Or is there any extra resistance as compared to a non-electric bike?

You're onto it.
People get so used to power assisted riding.
When it's no longer there it does feel like riding up a hill.
 
With the power turned off and the ebike on a stand, do the pedals turn freely when cranked forward? Or is there any extra resistance as compared to a non-electric bike?

I also have a Pedelec that is using Yamaha PW X that when it is on a stand and power is turned off - i hear the motor being engaged because of the noise when I turn the crank. I also feel the drag when pedaling unassisted.
 
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I also have a Giant Dirt E Pro 1 that is using Yamaha PW X that when it is on a stand and power is turned off - i hear the motor being engaged because of the noise when I turn the crank. I also feel the drag when pedaling unassisted.

Is the drag when pedaling forward on the stand, very significant compared to a non-electric bike? If it is, then there is failure of the free wheel clutch to disengage at the motor side. This is a warranty issue.
 
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I also have a Pedelec that is using Yamaha PW X that when it is on a stand and power is turned off - i hear the motor being engaged because of the noise when I turn the crank. I also feel the drag when pedaling unassisted.
I have a Road E1. I just checked and when I turn the crank with the battery out of the bike, I can hear gears turning inside the motor. If I turn the crank a bit slower than the rear wheel I can feel the resistance associated with the motor turning.

Is the motor intended to completely disengage from the crank when the assist is off?
Is the free wheel clutch on the motor side right at the crank or further in at the actual motor after some gearing
 
I have a Road E1. I just checked and when I turn the crank with the battery out of the bike, I can hear gears turning inside the motor. If I turn the crank a bit slower than the rear wheel I can feel the resistance associated with the motor turning.

Is the motor intended to completely disengage from the crank when the assist is off?
Is the free wheel clutch on the motor side right at the crank or further in at the actual motor after some gearing

Picture it like this, the chain ring receives power from your legs and/or the motor.

Your legs can pedal without the help of the motor such as in PAS 0. This is made possible by having a free wheel clutch from the motor so it would not be dragged along and produce "cogging" resistance (such as seen in direct drives).

The pedal also has a free wheel clutch. When you quickly stop pedaling , the motor takes more time to slow down to a stop, but it does without dragging your feet in the process.

Both clutches are supposed to function unnoticeably in the background without hampering the joy of riding your ebike.

1540872639154.png


PW-x has ISIS crank ends, other PW's have tapered square ends.

Below is the schematics on the clutch at the pedal side (illustration from Yamaha PW-X official site).

1540900883793.png
 
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Thanks TC, was aware of the clutches but didn't know how far in the one-way on the motor is. Per the picture above it shows there are at least two gears (Secondary Gear and Secondary Pinion) spinning when you pedal in manual. Hard to say if the load I am feeling is these or the motor spinning along with them. I will pull the motor cover off the other side this weekend and see if the oneway is working. .

Appreciate the above as I couldn't find any info on where the parts are located.
 
Pedaling a 50lbs bike unassisted sort of , kind of , defeats the purpose of getting an eBike , no ?

Yes I concur. What is the purpose of having an E-bike, when you are turning off the power? Perhaps just get one of those clip on motors for the front or back wheel (for steep inclines) and save the $$$ instead of buying a full E-bike IMO. I don't get it either.
 
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