Shimano EP8 bearings

[Messy]

Hi gents!
Any chance someone did the overhaul bearing maintenance on their EP8 and has the used bearings used by shimano somewhere at hand?
I'm looking for the list of bearings used together with part numbers
I know eBike Motor repair website has the kit together with THEIR part numbers, but thats not the original parts.
I would really appreciate the help

 

[steve_sordy]

@Messy Shimano advise that their motor is not designed to be repairable, not surprisingly they don't list any spares or details of any kind.
If someone has dismantled a motor, they will have determined for themselves what size bearings are required. You have the opportunity to copy them and/or substitute a higher quality bearing.
If that is your motor in the photo, you could also measure the bearings for yourself.

 

[Messy]

Thanks @steve_sordy for input. I'm conscious Shimano are useless in their approach to customer/service of their motors.
That's the reason I'm trying to abuse you guys a bit here on the forums before opening my own motor and servicing it
Just gathering as much info and parts as possible before removing the unit for service from the bike
ps. the pic attached is just for attention, as it's just a random one from net

 

[bctracing]

great

 

[InRustWeTrust]

@Bearing Man maybe now, i know he is doing service on shimano motors.

 

[Bearing Man]

Thanks @steve_sordy for input. I'm conscious Shimano are useless in their approach to customer/service of their motors.
That's the reason I'm trying to abuse you guys a bit here on the forums before opening my own motor and servicing it
Just gathering as much info and parts as possible before removing the unit for service from the bike
ps. the pic attached is just for attention, as it's just a random one from net

We do sell the bearing kits for the EP8, you can find them here if you need anything: Shimano EP8 - eBike Motor Centre

 

[akhazard]

Shimano uses KOYO bearings in their ep8 motors. I couldn't find them for sale in my country, so I installed NTN bearings.

 

[revelpaul]

Shimano uses KOYO bearings in their ep8 motors. I couldn't find them for sale in my country, so I installed NTN bearings.

I just tore down an EP8 that was making a lot of noise. I found 3 different bearing brands. NTN for the main spindle bearings, NMB for the gear shafts, and LFB (seems to be a Chinese brand) for the motor rotor. It doesn't really matter what brand you replace with, but I would choose higher quality electric motor rated bearings for the rotor, as it's spinning at high RPM.
The inboard motor rotor bearing was crunchy. I had to desolder the phase leads from the motor controller board to access this bearing. They definitely didn't design this thing to be repaired. Pictures here: Shimano EP8 Motor repair

 

[Mosheas]

Does anyone know the dimensions of the EP8 bearings and model?

 

[Bearing Man]

Does anyone know the dimensions of the EP8 bearings and model?

Yes, I do. You can buy them as a kit or individually from us or any of our partners worldwide https://www.ebikemotorcentre.com

 

[revelpaul]

Does anyone know the dimensions of the EP8 bearings and model?

The motor rotor has a 6900zz and a 6901z.
The 1st gear shaft and 2nd gear shaft have two 608zz each.
BB spindle has a 6805zz and 6808. Not sure about the needle roller bearing.
EDIT: The needle bearing is 25mm ID x 29mm OD x 17mm (more like 16.6mm since it doesn't have a outer race) long.

 

[Mosheas]

The motor rotor has a 6900zz and a 6901z.
The 1st gear shaft and 2nd gear shaft have two 608zz each.
BB spindle has a 6805zz and 6808. Not sure about the needle roller bearing.
EDIT: The needle bearing is 25mm ID x 29mm OD x 17mm (more like 16.6mm since it doesn't have a outer race) long.

Thank you.. Very helpful.
Is the BB spindle bearings Should be RS type?
Can you explain better about Dimensions of bearing needle bearing.
Thank you

 

[revelpaul]

Thank you.. Very helpful.
Is the BB spindle bearings Should be RS type?
Can you explain better about Dimensions of bearing needle bearing.
Thank you

The spindle bearings are just shielded not sealed (zz but some bearings are just labeled "z" but have shields on boths sides)... they are inboard of separate seals that keep them clean. I think it would be fine to use sealed (RS) type on the spinde though. The added drag is probably miniscule and it would add one more layer of protection.
Regarding the needle bearing, this one I think would work: Needle roller and cage assemblies K25-29-17-INA - 25x29x17 mm | 123Bearing
It measures 17mm, but the one I measured in the EP8 was closer to 16.6mm. I don't have a motor open right now, but I think it would be ok.

 

[Mosheas]

The spindle bearings are just shielded not sealed (zz but some bearings are just labeled "z" but have shields on boths sides)... they are inboard of separate seals that keep them clean. I think it would be fine to use sealed (RS) type on the spinde though. The added drag is probably miniscule and it would add one more layer of protection.
Regarding the needle bearing, this one I think would work: Needle roller and cage assemblies K25-29-17-INA - 25x29x17 mm | 123Bearing
It measures 17mm, but the one I measured in the EP8 was closer to 16.6mm. I don't have a motor open right now, but I think it would be ok.

And a final question, what do you think is minimum recommended to use the accuracy standard abec 1-7 ?
Thank you very much for your help.

 

[revelpaul]

And a final question, what do you think is minimum recommended to use the accuracy standard abec 1-7 ?
Thank you very much for your help.

I don't think the ABEC rating is important. It's a measure of the tolerances and a higher tolerance class doesn't mean that they will last longer. I would just choose bearings from a reputable company. I realize that I recommended "electric motor quality" bearings for the rotor, but really, I think as long as you aren't putting no-name bearings in, it should last as long as the stock bearings. Probably longer than the cheap stock bearings I just replaced on the rotor shaft. It's strange that Shimano used the cheapest bearings on the rotor shaft that spins at 3600 RPM.

 

[Mosheas]

I don't think the ABEC rating is important. It's a measure of the tolerances and a higher tolerance class doesn't mean that they will last longer. I would just choose bearings from a reputable company. I realize that I recommended "electric motor quality" bearings for the rotor, but really, I think as long as you aren't putting no-name bearings in, it should last as long as the stock bearings. Probably longer than the cheap stock bearings I just replaced on the rotor shaft. It's strange that Shimano used the cheapest bearings on the rotor shaft that spins at 3600 RPM.

Thank you very much for your help.

 

[mistermtb]

Can you guys please share information about sealing around two halves of motor housing? Is this some kind of liquiud seal or is it just rubber seal? I'm planning dissasemble my unit just for taking care of it as I'm after warranty now. Motor has slightly over 2500km on it, no issues so far.

 

[akhazard]

Can you guys please share information about sealing around two halves of motor housing? Is this some kind of liquiud seal or is it just rubber seal? I'm planning dissasemble my unit just for taking care of it as I'm after warranty now. Motor has slightly over 2500km on it, no issues so far.

I used a sealant for car engines. Black sealant-gasket. I have disassembled and assembled the engine twice already, both times I used this sealant, I did not find any traces of moisture.

 

[Turtlehead]

We do sell the bearing kits for the EP8, you can find them here if you need anything: Shimano EP8 - eBike Motor Centre

I’ve heard there are tamper concerns of bricking a motor, any insights on this?
Is there a place with good instructions/video on how to properly servicing without bricking things?

 

[mistermtb]

Guys, I have my ep8 disassembled on my bench, as I'm waiting for one bearing I need to replace. Do anyone need any specific pictures of the inside of the motor? I will be assembling the motor probably on Wednesday, so you have time to post your questions. Cheers

 

[Bearing Man]

I’ve heard there are tamper concerns of bricking a motor, any insights on this?
Is there a place with good instructions/video on how to properly servicing without bricking things?

There is no special "thing" inside any of these motors, that will stop them working if you open them up. Most people "brick" their own motors by breaking the ribbon wires on the pcb and torque sensor. As long as you're very carful, you should be fine.

 

[Putti]

Anyone knows the bearing sealings sizes? Or where to get new ones?

 

[JimmyBoy]

See STEPS E8000 Motor Service