EP801 low frequency vibration through pedals in Turbo mode.

[A22]

Each time I put the EP801 into Turbo/ highest assist mode and go up a steep hill I get a low frequency vibration through the pedals. It feels like a large bearing is damaged or the power is slowly pulsing on and off during the crank cycle but then when i drop the power or go to a flat area where Im not asking as much assistance from the motor the vibration goes away. No error codes showing for any of the system.
Pedal and crank bearing seem fine.

Has anyone else experienced this?

I’d drop it into the LBS but it just went out of business.

 

[Stihldog]

Firmware update? While in turbo mode, are you close to the speed assist limit? Magnet sensor correctly positioned?

Doesn’t sound like an internal cog/bearing issue,…elevate the bike and try to replicate the feeling/sound.

 

[timo2824]

Each time I put the EP801 into Turbo/ highest assist mode and go up a steep hill I get a low frequency vibration through the pedals. It feels like a large bearing is damaged or the power is slowly pulsing on and off during the crank cycle but then when i drop the power or go to a flat area where Im not asking as much assistance from the motor the vibration goes away. No error codes showing for any of the system.
Pedal and crank bearing seem fine.

Has anyone else experienced this?

I’d drop it into the LBS but it just went out of business.

What's your cadence when you're feeling it?

 

[A22]

Firmware update? While in turbo mode, are you close to the speed assist limit? Magnet sensor correctly positioned?

Doesn’t sound like an internal cog/bearing issue,…elevate the bike and try to replicate the feeling/sound.

Magnet is well clear of sensor and it has the latest firmware. The hill I ride up everyday is steep so I’m usually going about ~11kph. The vibration is still present, even more noticeable at lower cadences/ speed.

When I try replicating the issue off bike I don’t get anything. I think it’s because I can’t put as much power through the pedals.

 

[A22]

What's your cadence when you're feeling it?

As low as 65 but normally I’m a between 85-95. The lower the cadence the more the feeling comes through. As soon as I get to the top of the hill or lower the assistance the vibration disappears. Could it be from the motor pulsing through the crank cycle when high levels of assistance/ torque is required?

 

[TorAtle]

Same here but only noticeable in turbo on very low cadences.

 

[A22]

Same here but only noticeable in turbo on very low cadences.

I first noticed it after about 50km, it’s slowly gotten slightly more prominent now that I’ve done 550km. Before your comment I hadn’t seen anything else on internet about it. Hopefully it’s harmless…

 

[MOG]

I think mine does the same. New bike, only about 50 km max. Very low cadence in Boost. Vibration through cranks but feels more electrical than pure mechanical

 

[knut7]

I've felt that on a demo bike or two. Feels like the three phase AC timing is off. Never found out what it was though.

 

[timo2824]

I've felt that on a demo bike or two. Feels like the three phase AC timing is off. Never found out what it was though.

These are probably pulse width modulated DC motors.

OP, It might be because it's sensing you speed up and slow down on the cranking. Take it to a shop and have them add 1/4 or 1/2 second of overrun and see if it goes away.

 

[knut7]

These are probably pulse width modulated DC motors.

OP, It might be because it's sensing you speed up and slow down on the cranking. Take it to a shop and have them add 1/4 or 1/2 second of overrun and see if it goes away.

Yeah, of course, pwm. Confusing it with my car :/

 

[Turtlehead]

Mine was working totally fine, and then today on a climb started doing this. It came on really weird feeling on a steep climb.
I'm convinced it must be a bearing - but I've never taken one of these apart.
Have you figured out what was causing this?
Low cadence pedaling in any assist mode and I feel this.

 

[Borbea]

Worn chainring

 

[MOG]

Bearing and worn chainring might be a cause except that, in my case, it has been present straight out of the box on a brand new bike. Still does it now after 150km of riding!