Repair/replace Shim...
 

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Repair/replace Shimano Ep8 motor

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My motor is giving sensor errors and out of warranty.

what are the options? Is anyone repairing these? How much is a replacement? ( I’ve found some on eBay but I thought I saw somewhere had them new in a sale but nor finding it searching on here or via google)


 
Posted : 29/09/2023 11:32 am
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https://singletrackmag.com/forum/topic/psa-new-shimano-ep8-motors-are-580-at-wiggle/

It was Wiggle, but the link is now dead and they've removed the item


 
Posted : 29/09/2023 11:54 am
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E-bike repairs on FB

pretty sure they fix Shimano


 
Posted : 29/09/2023 12:07 pm
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take it to a dedicated shimano steps dealer - they can send it to madison who may give you money off a warrentied new one.


 
Posted : 29/09/2023 12:16 pm
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Yep doing anything other than going to a dealer will cost a lot and you still won't have a warranty. There are no repair places that can fix electrical/sensor issues and somtimes Madison are generous with out of warranty replacements.

If you've tampered with any settings via ST Unlocker etc put it all back to stock settings first!

Possibly another option if you want to save money and don't mind less assistance (but more range) is fitting a lower spec motor https://www.rczbikeshop.com/default/shimano-drive-unit-steps-du-e6100-25km-h-kdue6100.html


 
Posted : 29/09/2023 1:07 pm
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I'm assuming there is a cable running from the magnet sensor near the back wheel to the motor - have you checked that this is not damaged/faulty?


 
Posted : 29/09/2023 1:12 pm
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Don’t think it’s speed sensor fault - if not connected show as “sensor initialisation error”. I *think* it’s the internal torque sensor that’s failed. It sometimes throws error immediately, sometimes will let me pedal a bit before going into error mode. have been in very wet Cumbria for the week so hoped a night by the radiator would fix it but it hasn’t.

will drop motor when at home and check cables and connections. But not hopeful.

errors are 20 30 and 51 on various restarts - sensor abnormality / failure in drive unit.


 
Posted : 29/09/2023 2:25 pm
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Getting it plugged in at a Shimano Service Centre should determine what the problem is?


 
Posted : 29/09/2023 5:09 pm
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@oldfart

Ridiculously, a service centre connecting their PC gives no more detail on error messages than the mobile app you have as an end user.  'sensor failure in motor' without specifying which one.

Shop thinks likely wiring issue rather than motor and has ordered wiring loom to try replacing bit by bit.  Almost the worst sort of failure - erratic and no info.


 
Posted : 19/10/2023 9:34 am
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Shop thinks likely wiring issue rather than motor

sounds like wishful thinking to me....if the error is saying sensor failure , all the sensors - except the speed sensor - are part of the motor itself, nothing to do with the wiring loom.

Everyone I know with the shimano motor , when they get the sensor failure fault codes, has required a new motor to fix.


 
Posted : 19/10/2023 10:45 am
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I'd like to get hold of a broken Shimano (or any ebike motor) at some point.

I'm an engineer - familiar tinkering with drives/control systems etc down to oscilloscope level and have a good relationships with a company that repairs stuff that I can't fix.
I'm sure these Shimano load cell/strain guage/thermistor/whatever sensors they have are repairable.

I have a Steps6000 in my commuter bike but it's been faultless


 
Posted : 19/10/2023 11:06 am
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I’m sure these Shimano load cell/strain guage/thermistor/whatever sensors they have are repairable.

Take a look on emtb forums, theres pics of the internals, oscilloscope readings etc.

From my rough understanding...

The strain gauge is glued to the axle, and wired to a circuit board that rotates with the axle and communicates wirelessly to a static circuit board in the motor shell. Replacing the axle and sensor assembly has been tried, but the everything is calibrated together in the factory, so the motor throws an error. Really you need access to the firmware or software that Shimano uses to update the calibration. Shimano didn't use great encryption on their earlier software so maybe it's hackable, but not without a lot of time/effort.

Perhaps you could just replicate a static torque value and transmit that instead, but by the time you get to this point, it may well be easier putting in a third party motor controller and BMS and just ditching the Shimano electronics altogether. I saw a video of someone who did exactly this somewhere.

‘sensor failure in motor’ without specifying which one

It's because none of them can be replaced. Regardless of which one, you'll need a new motor.


 
Posted : 19/10/2023 11:45 am
 FOG
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Yep new motor time. When mine died my local Shimano Service Centre contacted Madison and I got an 'assisted purchase ' which meant I got a new motor considerably cheaper than list. I can't understand why some hacker hasn't cracked Shimano's systems. If you can hack major banks surely you can hack an ebike control! Probably not enough money in it.


 
Posted : 19/10/2023 11:59 am

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