Shimano EP8 Rubbing/Vibration feeling

[Turtlehead]

Was riding my orbea rise today. Bike and motor are out of warranty. I have unlocked it to the full NM and was climbing in boost. It was a fairly steep road climb, and suddenly something just felt "weird" - I immediately dropped from boost to trail mode and it seemed to go away.
As I continued to climb, I started playing around with pedaling cadence and assist mode.
It doesn't matter what assist mode I'm in, the harder I pedal, the more I feel something that I feel is like a rubbing that creates a vibration feeling through the cranks.
I'm trying to figure out if it's a bearing, or something else inside the motor.
It is still providing assist and still riding. No weird sounds yet.
As it's out of warranty, I'm pretty sure I'll split it apart and see if I can service it. Any advice on what to look for?

 

[Spiff]

If motor is out of warranty, then open it, it is even easier than E8000. In Spain we say: "From lost, to the river", which is the idiom for: "in for a penny, in for a pound" or " we're down the rabbit hole" , I like country specific idioms, ha ha.

Check for: lack of grease, missing teeth in gear , missing "roller" in sprag clutches, damaged bearing.

EP8 is similar to E8000:

STEPS E8000 Motor Service

 

[RustyIron]

I've never had an EP8 apart, but if cracking it open is as simple as you make it sound, I'd be all over it. If you're lucky, you can diagnose and repair the weird symptom before any substantial damage occurs. It would be a bummer to put it off, and then in a month find out that the motor is cratered because of a lack of lubrication that could have been easily resolved if addressed in a more timely manner.

 

[Mudrider]

yes i have noticed this on my ep801, at a certain cadence and load (mid to high) you get a vibration through the pedals it goes into what feels like a resonant frequency. I don't think its anything to worry about.

 

[Turtlehead]

If motor is out of warranty, then open it, it is even easier than E8000. In Spain we say: "From lost, to the river", which is the idiom for: "in for a penny, in for a pound" or " we're down the rabbit hole" , I like country specific idioms, ha ha.

Check for: lack of grease, missing teeth in gear , missing "roller" in sprag clutches, damaged bearing.

EP8 is similar to E8000:

STEPS E8000 Motor Service

thanks! if it's missing teeth or roller etc... is there a good place to find replacement parts? (I'm in the United States - not sure if that changes finding parts)

 

[Turtlehead]

yes i have noticed this on my ep801, at a certain cadence and load (mid to high) you get a vibration through the pedals it goes into what feels like a resonant frequency. I don't think its anything to worry about.

thanks, it's definitely a bad rubbing/vibration coming through - and it's never done it before and started suddenly on a big climb

 

[Turtlehead]

I've never had an EP8 apart, but if cracking it open is as simple as you make it sound, I'd be all over it. If you're lucky, you can diagnose and repair the weird symptom before any substantial damage occurs. It would be a bummer to put it off, and then in a month find out that the motor is cratered because of a lack of lubrication that could have been easily resolved if addressed in a more timely manner.

fingers crossed it's fixable!

 

[A22]

yes i have noticed this on my ep801, at a certain cadence and load (mid to high) you get a vibration through the pedals it goes into what feels like a resonant frequency. I don't think its anything to worry about.

Same here. For me it normally happens when the battery is less than 80%, cadence drops below 80rpm, full power/ turbo mode and going up a steep hill. I’m certain it’s an electrical type of issue like you describe and nothing to really worry about.

If I drop a few gears to increase rpm it goes away, if I change out of highest assist it goes away. If I have a full battery it doesn’t occur.

 

[Mudrider]

Same here. For me it normally happens when the battery is less than 80%, cadence drops below 80rpm, full power/ turbo mode and going up a steep hill. I’m certain it’s an electrical type of issue like you describe and nothing to really worry about.

If I drop a few gears to increase rpm it goes away, if I change out of highest assist it goes away. If I have a full battery it doesn’t occur.

the motor certainly has more poke at full battery that's for sure!

 

[Borbea]

I suspect the chainring. I had this and it was the chainring that was worn out.

 

[Turtlehead]

I suspect the chainring. I had this and it was the chainring that was worn out.

Will inspect. Only has 400 miles

 

[Turtlehead]

I’ve noticed it doesn’t happen on flat ground/no resistance
Only does it on climbs

 

[A22]

I’ve noticed it doesn’t happen on flat ground/no resistance
Only does it on climbs

Yes same for me, as soon as the load comes off the motor the vibration goes away. Chain ring is fine, bike has only done ~150km when I first noticed it.

 

[Turtlehead]

Yes same for me, as soon as the load comes off the motor the vibration goes away. Chain ring is fine, bike has only done ~150km when I first noticed it.

motor still running strong to this day? how many km now?

 

[A22]

motor still running strong to this day? how many km now?

Yeah the motors fine, around 500km now.

 

[Quantock Explorer]

I've noticed the same thing with my wife's bike. It happens when the cadence is low. Drop down a couple of gears and it goes away.
I put a new chain on the bike and updated the firmware at the same time (6 weeks ago). The problem started after this...

 

[mistermtb]

Last week I dissasembled and yesterday assembled my EP8 as I was out of warranty. Had 2600km on the clock, just a routine service. I can comfirm that the whole process is as easy as unscrew a couple of bolts. Had some struggle with this silicone seal around the two halves of casing, but eventualy managed to pry them with a flat screwdriver. While I was looking around and touching each bearing turns out one of them had a little play so I ordered new one and replaced it. After assembly and test ride I was shocked how quiet the motor is now. Since new I tought the noise the motor makes is normal, but turns out (I suspect) this bearing was broken since new. It didn't sound suspiciously loud or strange, but now I can compare and say it is a lot quieter than before.