taking apart rear hub for Hall sensor replacement

[crystaljohn]

I need to take my rear hub apart to replace the Hall sensors. Never done this before.

There is an external circlip on the axle which I presume is necessary to remove to enable the hub to be disassembled?

Does the 'sprocket cluster' need to be removed as well? Is the sprocket cluster called a 'Free wheel'?

Any other tips appreciated.

Wheel is from a Powercycle Cambridge e bike btw.

 

[crystaljohn]

I do appreciate the sprocket teeth are badly worn, so I would like to replace the 'cluster' at some point. I presume something like this is easily available?

 

[Andy-Mat]

I need to take my rear hub apart to replace the Hall sensors. Never done this before.

There is an external circlip on the axle which I presume is necessary to remove to enable the hub to be disassembled?

Does the 'sprocket cluster' need to be removed as well? Is the sprocket cluster called a 'Free wheel'?

Any other tips appreciated.

Wheel is from a Powercycle Cambridge e bike btw.View attachment 35539View attachment 35540View attachment 35540View attachment 35541

How are you certain that a sensor is defective? It may seem like a rude question, not intended so, but I wanted to help you make sure, as taking a motor apart is for some, a large undertaking.
But there are some good videos on YouTube that may help, once you are 100% certain.
For anyone not used to a Multi-Meter, it appears that an e-bike tester (also on YouTube!), is a VERY cheap and helpful investment!

regards
Andy

 

[crystaljohn]

Thanks for your reply Andy, much appreciated.

Despite testing the Hall sensors several times, I couldn't definitely find a fault with them.
I did find the testing problematic, as the 6:1 reduction ratio meant that as soon as I revolved the rear wheel backwards as slowly as I could manage, with just a few degrees of rotation the voltage was switching on and off so quickly it was hard to be absolutely certain; due to the reaction time of my digital meter, that things were happening as they should be.

I tried this test several times over the course of the last 6 months, each time I found the same difficulty in making an absolute decision that they were faulty or not.

Recently I removed the rear wheel and removed the cover plate, and whilst checking the continuity between the connection leads on the Hall sensors and the White nylon multi pin plug I noticed that the connection on the middle Hall sensors Ground wasn't properly connected to the thin wires in the loom. Bingo, I have located the reason for my C3 error showing on my LCD display and why the motor will not work, or so I thought. I extremely carefully resoldered the joint assuming that all would be working now, but unfortunately I still have the C3 error showing and a motor that doesn't work.

This is the reason I decided to attempt replacing the Hall sensors.

I wish I had know about the E bike tester that you have shown earlier on, it would certainly minimised a lot of the time I have spent fault finding.

 

[Andy-Mat]

Thanks for your reply Andy, much appreciated.

Despite testing the Hall sensors several times, I couldn't definitely find a fault with them.
I did find the testing problematic, as the 6:1 reduction ratio meant that as soon as I revolved the rear wheel backwards as slowly as I could manage, with just a few degrees of rotation the voltage was switching on and off so quickly it was hard to be absolutely certain; due to the reaction time of my digital meter, that things were happening as they should be.

I tried this test several times over the course of the last 6 months, each time I found the same difficulty in making an absolute decision that they were faulty or not.

Recently I removed the rear wheel and removed the cover plate, and whilst checking the continuity between the connection leads on the Hall sensors and the White nylon multi pin plug I noticed that the connection on the middle Hall sensors Ground wasn't properly connected to the thin wires in the loom. Bingo, I have located the reason for my C3 error showing on my LCD display and why the motor will not work, or so I thought. I extremely carefully resoldered the joint assuming that all would be working now, but unfortunately I still have the C3 error showing and a motor that doesn't work.

This is the reason I decided to attempt replacing the Hall sensors.

I wish I had know about the E bike tester that you have shown earlier on, it would certainly minimised a lot of the time I have spent fault finding.

Will you buy one? They are around 10 UK pounds from a UK based Supplier on ebay if I remember correctly, just look on there.
There are basically two versions, one with a round display for the motor signals, and one where the same LEDs are in a line.
I am told that the one with the circle is better and easier to understand, as in the video I sent you!
regards
Andy
PS. One day I am going to also buy one.
PPS. Chinese builders do not always use the same/correct plugs, you may need to "adjust" one to fit to your bike.

 

[crystaljohn]

Will you buy one? They are around 10 UK pounds from a UK based Supplier on ebay if I remember correctly, just look on there.
There are basically two versions, one with a round display for the motor signals, and one where the same LEDs are in a line.
I am told that the one with the circle is better and easier to understand, as in the video I sent you!
regards
Andy
PS. One day I am going to also buy one.
PPS. Chinese builders do not always use the same/correct plugs, you may need to "adjust" one to fit to your bike.

I did have a look on ebay, there are numerous testers available, the one you showed in you link seemed to correspond with the plugs I have on my setup too.
I will be buying one asap.

 

[Andy-Mat]

I did have a look on ebay, there are numerous testers available, the one you showed in you link seemed to correspond with the plugs I have on my setup too.
I will be buying one asap.

I am really interested in how you get on. I am sure that I am not alone.
Best of luck
Andy

 

[flecc]

I need to take my rear hub apart to replace the Hall sensors. Never done this before.

There is an external circlip on the axle which I presume is necessary to remove to enable the hub to be disassembled?

Does the 'sprocket cluster' need to be removed as well? Is the sprocket cluster called a 'Free wheel'?

Any other tips appreciated.

Wheel is from a Powercycle Cambridge e bike btw.View attachment 35539View attachment 35540View attachment 35540View attachment 35541

You may find this page on my Torq site useful.

The text below the photos of a typical motor's internals cover the components involved and the details on stripping the motor. Replacing the Hall sensors can be difficult though, as the first photo shows, the sensors and wiring are buried, glued in with shellac or similar and often laced too.

Your sprocket set is a Freewheel and not a Cassette. The mounting thread is standard and there's a range of these freewheels on the market. You do need a freewheel removal tool to get it off, not the very similar cassette removal tool.

Be aware that any connector on the motor leads will often not pass through the freewheel, so you may need to disassemble the connector and leads to change the freewheel.
.

 

[Scorpio]

Hi, I'm new to bikes but have rebuilt my hub (similar to yours), looking at your last photo I dont think you need to remove your gears. Hopefully somebody experienced can confirm.
The cover you have already removed lets you work on the hall sensors & the main cable through the axle.
I think I can see your hall sensors in your photo (they are small devices at the edge of the motor, each has 3 wires connected). Think of a clock face - your sensors are at 1 o'clock, 3, 6.
If your main motor wire came from the other end of the axle and through the gears it would be more difficult.

 

[crystaljohn]

Thanks for the link to your Torq site flecc, that is very helpful.
I have watched a few utube video replacing the Hall sensors and I think this is within my capabilities. I have located the Hall sensors, and resoldered a disconnected wire to the Ground of the middle sensor. I thought this might be the cure for my C3 error code and non working motor, but it's not, I still have the C3 error code displayed and the motor is not working.

I need to seperate the armature from the body of the motor to enable me to gain good access to the Hall sensors so as I can 'dig them out' of the Shellac which is fixing them in position.
I presume if I remove the external circlip which is retaining the armature it should withdraw?

 

[crystaljohn]

looks to me as though I will have to remove the Freewheel and then undo a nut on the axle to allow the armature to be withdrawn from the motor body. Anyone confirm that this is the way forward please.

 

[flecc]

On the one I illustrated it's just remove the left hand wheel nut to withdraw the armature.

The freewheel doesn't have to be removed but of course access to the Hall sensors will be awkward with it in the way.
.

 

[crystaljohn]

On the one I illustrated it's just remove the left hand wheel nut to withdraw the armature.

The freewheel doesn't have to be removed but of course access to the Hall sensors will be awkward with it in the way.
.

With my motor, The hall sensors are on the left hand side of the bike, opposite the Freewheel. I do need to separate the armature to enable me to 'dig out' the Hall sensors.

Still haven't worked out how it all comes apart atm, I'm sure I must remove the Freewheel first ( I will borrow the removal tool from a friend next week as delivery of a new tool from China via ebay will probably take a long time)

 

[Andy-Mat]

Are you going to document this repair, with photos and put them on Pedelec?
Andy

 

[Scorpio]

Hi, the 2 links below should give you an idea of what to expect inside. Both are front wheels, but I think they are the same inside as your rear.

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Hi, my trusty MK.1 Torq has always had a bit of a growl y motor but reliable. A recelle'd battery last year gave it a new lease of life. But to day it seemed to use up battery capacity fairly quickly and motor was not pulling as well/more noisy on a 4 mile trip. Then on a gentle climb, it gave...

www.pedelecs.co.uk

Your steps : Remove gear cluster - remove 6 bolts and remove side cover - pull clutch/3 planet gears off the shaft (photo 9275) - remove small gear cog (See photo (9274) - remove circlip from shaft.
Photo 9280 shows one of the hall sensors. Then read the text for best way to split the hub motor.

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My rebuild, with photos & links I found useful.

Hope it helps !

 

[Nealh]

To remove the internals usually there is a nut inboard of the drop out on the LHS, a thin washer & rubber seal protecting a bearing. The face plate RHS is removed and then the internals can be withdrawn.

 

[crystaljohn]

Thanks for all the very helpful advice. I am going to put the disassembly of the motor on hold for the moment as I have now re-tested the Hall sensors yet again , this time with the aid of the wheels axle held vertically firmly in a Workmate vice. This has enabled me to rotate the armature more slowly now I have everything exposed, and with more control .
Numerous previous tests had left me uncertain if they were faulty or not, as revolving the wheel whilst it was in situ in the bike was switching the voltage so quickly on/off my digital meter was struggling to display the changing voltage clearly enough.

Since the installation of the new controller I have been unable to get my bike to work, as all that happens when I activate the throttle is I get a C3 error displayed on the LCD.

I have a brand new (controller and LCD display *) which I assumed is working correctly, but I am now in doubt. I have now ordered a Brushless motor controller tester thanks to the heads up by Andy-Matt so I hope to be able to test my new controller when the tester arrives.

http://www.pswpower.com/ven.php?cargo.2016-3f-3f7c * new controller