Shimano EP8 Motor repair

PaulD

PaulD

1 kW
Joined
Aug 28, 2008
Messages
427
Location
Ashland, OR, USA
Planned obsolescence and poor after sales service really is becoming a pet peeve of mine. Spare parts are rarely available for ebikes, and it's leading to some pretty expensive paperweights in the high end ebike world. I dug into this motor that was out of warranty, for a local shop that said it was making a lot of noise.
1716323590654.png
1716322081755.png
It definitely doesn't look like they intended it to be serviceable. I had to de-solder the controller board to access the rotor bearings. :oop:


1716321940842.png


This bearing was crunchy. I'll pull it off, and replace it and hope I didn't damage anything with my big ol desoldering pump.
1716323141683.png
Despite the issues and the planned obsolescence, it's pretty nice. Nice IPM configuration, very light, potted stator, no hall sensors, no temp sensor (I assume it has some kind of i2t algorithm)
1716323441351.png
Some globs of glue on the back of the rotor.
 
Hi, did you have any problems after rebuilding the motor and putting it back in the bike? I'm getting E01050 error. Thanks
 
UKJ said:
Hi, did you have any problems after rebuilding the motor and putting it back in the bike? I'm getting E01050 error. Thanks
Click to expand...
It looks like that is a torque sensor error. The torque sensor and it's cable definitely seem like the easiest bits to damage during disassembly and re-assembly.
I haven't heard anything from the shop that I did the work for, so I assume all is well. I'll check in with them.
 
PaulD said:
It looks like that is a torque sensor error. The torque sensor and it's cable definitely seem like the easiest bits to damage during disassembly and re-assembly.
I haven't heard anything from the shop that I did the work for, so I assume all is well. I'll check in with them.
Click to expand...
Hello, what's happened? Everything is running well? Thanks
 
PaulD said:
Planned obsolescence and poor after sales service really is becoming a pet peeve of mine. Spare parts are rarely available for ebikes, and it's leading to some pretty expensive paperweights in the high end ebike world.
Click to expand...

If you listen to what they're telling you, you'll know that those things are traps for the foolish to buy, and in some cases for the elite foolish to waste their time trying to fix.

Recycle. Warn others.
 
biker.alej said:
Hello, what's happened? Everything is running well? Thanks
Click to expand...
The shop says it still hasn't been installed. I assume the customer got a replacement motor. I might try to grab it and find a bike to test it on.
Chalo said:
If you listen to what they're telling you, you'll know that those things are traps for the foolish to buy, and in some cases for the elite foolish to waste their time trying to fix.
Click to expand...
Some of these drives have relatively easy issues that are well worth fixing, others not so much. Maybe its my elite foolishness, but I think they are worth the time to save them from being a waste. Maybe someone more elite (and less foolish, maybe?) will have the skill and time to sniff the comm messages and develop open source drop-in replacement bits. Just such a project is underway to rescue Faraday ebikes with dead batteries. I'll post about that in the near future.
As much as you and I and others dislike OE proprietary systems, there are a ton of them out there, and people will keep buying them. We can complain all we want, but they are more reliable than most DIY systems, and I think with some effort, we can help make them more repairable and not end up in the landfill.
 
PaulD said:
As much as you and I and others dislike OE proprietary systems, there are a ton of them out there, and people will keep buying them. We can complain all we want, but they are more reliable than most DIY systems, and I think with some effort, we can help make them more repairable and not end up in the landfill.
Click to expand...

How much is your time worth? Mine is worth more than the value of a wretched bike that was designed to resist being fixed from day one.

Because I work at a community bike shop, I have some oversight to help determine whether my time is being profitably used. So far, cheap and generic e-bikes are profitable, maybe and maybe not as much as ordinary pedal bikes. But brand name, closed system e-bikes are a resource loss so far. They spent extra design and tech making those bikes so that they wouldn't be fixable going forward. That's not only enough justification to warn people against buying such e-bikes-- it's enough to advise against buying any bikes from those brands of mercenary scum.
 
Chalo said:
How much is your time worth? Mine is worth more than the value of a wretched bike that was designed to resist being fixed from day one.

Because I work at a community bike shop, I have some oversight to help determine whether my time is being profitably used. So far, cheap and generic e-bikes are profitable, maybe and maybe not as much as ordinary pedal bikes. But brand name, closed system e-bikes are a resource loss so far. They spent extra design and tech making those bikes so that they wouldn't be fixable going forward. That's not only enough justification to warn people against buying such e-bikes-- it's enough to advise against buying any bikes from those brands of mercenary scum.
Click to expand...

I think part of me likes the challenge. Despite their lack of serviceability, these systems generally work better and are (usually) safer and more reliable. My goal with developing a mid-drive kit was attempting to bridge that gap.

Also, normie customers like buying from a company that they have heard of and will likely be still in business next week.
In a sad kind of way, the DIY movement seems to be failing at convincing customers that they should learn enough to be able to work on their bike. Most people just don't have the time or interest. They want to be able to drop it off at the bike shop for them to just plop a replacement unit in.

Most of the bike shops around here will not touch DIY builds, or even cheap generic stuff like Rad or Lectric. They don't have the knowledge beyond just replacing basic parts. And customers are more willing to drop hundreds of dollars on repair if their bike cost $10k, not $1K.

I'm not saying that you should stop advising people to avoid closed system bikes, just that it won't work... that's why I want to engineer solutions. I find things easier to fix than people and culture.
 
PaulD said:
Planned obsolescence and poor after sales service really is becoming a pet peeve of mine. Spare parts are rarely available for ebikes, and it's leading to some pretty expensive paperweights in the high end ebike world. I dug into this motor that was out of warranty, for a local shop that said it was making a lot of noise.
View attachment 353305
View attachment 353302
It definitely doesn't look like they intended it to be serviceable. I had to de-solder the controller board to access the rotor bearings. :oop:


View attachment 353301


This bearing was crunchy. I'll pull it off, and replace it and hope I didn't damage anything with my big ol desoldering pump.
View attachment 353303
Despite the issues and the planned obsolescence, it's pretty nice. Nice IPM configuration, very light, potted stator, no hall sensors, no temp sensor (I assume it has some kind of i2t algorithm)
View attachment 353304
Some globs of glue on the back of the rotor.
Click to expand...
Hi Paul. Do you have some more detailed info on the Motor bearings and what bearing puller did you use the replace and pull the new bearings?
Also that 3 desolded parts need to be solded again when mounting or just with the 3 screws gets tight?
I am thinking to try to do this replacement but I am a bit scared. If you have more info please send it to be more driven on this operation. Thank you!
 
Did you confirm that the problem is coming from the motor bearings? Best to make sure it isn't something else before attempting to remove the circuit board. I didn't make any other videos, and I don't have the motor anymore.
I used a standard bearing splitter like this: https://www.harborfreight.com/bearing-separator-with-12-in-to-4-38-in-jaw-capacity-63662.html
The bearing I replaced was a 6901 (closest to the gear). The bearing on the other side I *think* is 6900.
And yes, definitely resolder the circuit board when reassembling!! I suggest finding a friend that has some electronics experience to help you.
 
PaulD said:
Did you confirm that the problem is coming from the motor bearings? Best to make sure it isn't something else before attempting to remove the circuit board. I didn't make any other videos, and I don't have the motor anymore.
I used a standard bearing splitter like this: https://www.harborfreight.com/bearing-separator-with-12-in-to-4-38-in-jaw-capacity-63662.html
The bearing I replaced was a 6901 (closest to the gear). The bearing on the other side I *think* is 6900.
And yes, definitely resolder the circuit board when reassembling!! I suggest finding a friend that has some electronics experience to help you.
Click to expand...
Thank you Paul for your input. I will review all the other bearings before to make another step. I really thank you your support.
 
PaulD said:
And customers are more willing to drop hundreds of dollars on repair if their bike cost $10k, not $1K.

I'm not saying that you should stop advising people to avoid closed system bikes, just that it won't work... that's why I want to engineer solutions. I find things easier to fix than people and culture.
Click to expand...
It's definitely a subculture thing. A decade back I took a bike frame to a 'bike' paint shop here in the hope of getting it resprayed. It was just an ordinary old mountain bike, but a favorite of mine and I was rebuilding it like new. I was quoted over $1000 for the paint and decals. Inside the shop there were not a few fancy old racers from the 1970's etc, retro bikes that were selling for 5 and 8 grand plus. The owners were prepared to pay the big bucks, me I just went home and polished it by hand and then put black vinyl collars around the worst sections. It looked quite good when I was finished too! If it had been one of my motorcycles I wouldn't have hesitated paying one or two grand. But pushbike?

YUKON 02.jpg

I met a guy on the train a couple of years back and he had some flash German e-bike, he'd paid aussie-$18,000 for it he told me. It was a nice bike for sure, but 18k? Each to his own hey.
Good job on the motor repair BTW. I might have tried that myself, but I might have botched it too :LOL:
 
qwerkus said:
Can anyone explain why that iron lams on the rotor have this particular shape ?
Click to expand...
Those gaps are called flux barriers.
They, and the other features on the rotor are for shaping the mag field to whatever the engineers and FEMM(Finite Element Method Magnetics) thought best;
iu


iu
 
Last edited:
A-DamW said:
Those gaps are called flux barriers.
They, and the other features on the rotor are for shaping the mag field to whatever the engineers and FEMM(Finite Element Method Magnetics) thought best;
iu


iu
Click to expand...
Cool - thanks for the explanation. So essentially this design converts an ipm into a segmented ipm ? AFAIK that reduces cogging and allows for higher speeds at the cost of slightly lower torque.
 
You must log in or register to reply here.
Back
Top