Aikema 250W hub motor opening problem

[sarac]

Hi! I have an Aikema 250W hub motor for 10 years. It has traveled approx. 15K km and now I wanted to take it apart and lubricate it (with synthetic lubricant) but I don't know how. I guess that side cover needs to be unscrewed somehow, so I unscrewed the only three screws on it. I also saw that for some engines you need to have a special unscrewing tool (video below). Do I need such a tool? In the meantime, I have another problem, after I unscrewed those three screws, my engine doesn't work anymore. I can hear it spinning but it not transmit power to the wheel. I tried changing the phases on the controller (all 6 combinations) but it didn't help. What's wrong here? This is my motor:





Video with tool:

 

[Nealh]

The three screws hold the clutch mechanism in place inside the hub. it is likely you have disturbe the clutch and now it doesn't engage
Did you refit the three screws before trying the motor again.



The way to open these hubs is to fabricate a flat bar and either drill a hole in it to go ver the axle or cut an arc out so it sits around the axle, one then has to align/drill teo clearance holes so that two of the tapped holes can be utilised with slightly longer machine thread bolts . One then can apply acw leaverage to undo the hidden threaded cover plate, removing all three cluthc plate screws isn't required .

 

[saneagle]

Hi! I have an Aikema 250W hub motor for 10 years. It has traveled approx. 15K km and now I wanted to take it apart and lubricate it (with synthetic lubricant) but I don't know how. I guess that side cover needs to be unscrewed somehow, so I unscrewed the only three screws on it. I also saw that for some engines you need to have a special unscrewing tool (video below). Do I need such a tool? In the meantime, I have another problem, after I unscrewed those three screws, my engine doesn't work anymore. I can hear it spinning but it not transmit power to the wheel. I tried changing the phases on the controller (all 6 combinations) but it didn't help. What's wrong here? This is my motor:





Video with tool:

When you put the screws back in, they have to line up with the threads in the clutch, which is a bit awkward to achieve because you can't easily rotate the clutch to line up. Are you sure the screws went into the threads?

To open the motor, you remove one of more screws and insert some device into the hole/s that you can use to rotate the side-plate anticlockwise to screw it off. You will almost certainly need to heat up the hub between the spokes to a temperature just too hot to touch, otherwise it won't turn.

The first time I did it, I removed one screw and inserted a cap-head screw and washer, heated up the hub, then bashed the screw from the side with a hammer and screwdriver. After a bit of bashing, the screws bend and I worried about the thread getting damaged, so I used a new screw in a new hole to continue.

Draw a pencil line across the join so that you can see if anything moves.

If you like fabricating stuff, you can make some sort of lever attached to a piece with three holes that match the three clutch holes and a central hole big enough to clear the raised part of the motor.

 

[Sturmey]

Is it necessary to re-lube a motor? The reason I ask is because my Yose motor have clocked up high milage (20K miles plus) without ever been opened. I have had to open another high mileage motor to replace of a noisy bearing and added a small amount of silicon grease when reassembling in this case.
I did accidentally go through a flood lately (over a foot high) which came up over both the front motor axle and also the bottom bracket for a few seconds. The bottom bracket failed shortly afterwards but the motor seems OK so far. I would say this motor could perhaps benefit from inspection but I have used it hard and regularly since so am hoping that the heat will have dried it out.

 

[thelarkbox]

Im a strong believer in ' if it aint broke dont fix it', unless your 100% confident in the dis/re-assembly procedures..

threadlocking the disk brake screws was the only waterproofing/weatherproofing advice given to me for a new kit install..

 

[sarac]

Did you refit the three screws before trying the motor again.

Yes, I refit the screws back in and they definitely got into some threads.

 

[sarac]

When you put the screws back in, they have to line up with the threads in the clutch, which is a bit awkward to achieve because you can't easily rotate the clutch to line up. Are you sure the screws went into the threads?

To open the motor, you remove one of more screws and insert some device into the hole/s that you can use to rotate the side-plate anticlockwise to screw it off. You will almost certainly need to heat up the hub between the spokes to a temperature just too hot to touch, otherwise it won't turn.

The first time I did it, I removed one screw and inserted a cap-head screw and washer, heated up the hub, then bashed the screw from the side with a hammer and screwdriver. After a bit of bashing, the screws bend and I worried about the thread getting damaged, so I used a new screw in a new hole to continue.

Draw a pencil line across the join so that you can see if anything moves.

If you like fabricating stuff, you can make some sort of lever attached to a piece with three holes that match the three clutch holes and a central hole big enough to clear the raised part of the motor.

I refit the screws back in and they definitely got into some threads but obviously they didn't catch those clutch threads. If one screw is successfully screwed into the clutch, does that mean that the other two are also lined up with the threads in the clutch or each screw is a story for itself?

Thanks for the advice! I think I'll buy some cap-head screws and try this with heating the hub.

 

[Nealh]

Personally I don't like smashing cap head screws to try and loosen the face plate and much prefer leverage via a flat bar and if need be a tap with club hammer to start the thread off. A wide bit of ali flat bar is easy to dril an arc or hole to go over the axle and a couple of the clutch holes aligned isn't hard to do.

 

[Nealh]

Is it necessary to re-lube a motor? The reason I ask is because my Yose motor have clocked up high milage (20K miles plus) without ever been opened. I have had to open another high mileage motor to replace of a noisy bearing and added a small amount of silicon grease when reassembling in this case.
I did accidentally go through a flood lately (over a foot high) which came up over both the front motor axle and also the bottom bracket for a few seconds. The bottom bracket failed shortly afterwards but the motor seems OK so far. I would say this motor could perhaps benefit from inspection but I have used it hard and regularly since so am hoping that the heat will have dried it out.

It won't hurt to carry out a quick service/inspection if you have the time and inclination to do so. Even with new hubs I have added extra grease simly because some have very little to start with.

Any hub with a six screw face plate is far easier to open then a hidden fine screw one , it all depends if one has a leaverage bar to open in the first place or has to make one up.

 

[saneagle]

I refit the screws back in and they definitely got into some threads but obviously they didn't catch those clutch threads. If one screw is successfully screwed into the clutch, does that mean that the other two are also lined up with the threads in the clutch or each screw is a story for itself?

Thanks for the advice! I think I'll buy some cap-head screws and try this with heating the hub.

The clutch is a self-contained complete unit, so you can't really do anything that would affect its operation by removing and replacing the screws. There are three reasons why the clutch wouldn't work that I can think of:

1. Motor is turning in the wrong direction. That's quite common with controllers that have self-learning wires if someone reconnects the wires - solved by re-doing the self-learning procedure. It could also happen if the motor were disconnected and reconnected with a different phase wire sequence.

2. The clutch was disassembled and reassembled with the centre part inverted. You didn't take the clutch out, so that couldn't have happened.

3. Rusty clutch due to water ingress. The roller springs are very thin and easly get destroyed by rust, and the rust can jam the rollers directly. Was there some reason that you decided to service your motor?

 

[sarac]

The clutch is a self-contained complete unit, so you can't really do anything that would affect its operation by removing and replacing the screws. There are three reasons why the clutch wouldn't work that I can think of:

1. Motor is turning in the wrong direction. That's quite common with controllers that have self-learning wires if someone reconnects the wires - solved by re-doing the self-learning procedure. It could also happen if the motor were disconnected and reconnected with a different phase wire sequence.

2. The clutch was disassembled and reassembled with the centre part inverted. You didn't take the clutch out, so that couldn't have happened.

3. Rusty clutch due to water ingress. The roller springs are very thin and easly get destroyed by rust, and the rust can jam the rollers directly. Was there some reason that you decided to service your motor?

The engine was running perfectly fine until then. I was changing a broken rim, so I decided to disassemble the engine and lubricate it at the same time.
I think I'll buy or try to make this thing https://www.aliexpress.com/i/1005001450711323.html

 

[saneagle]

The engine was running perfectly fine until then. I was changing a broken rim, so I decided to disassemble the engine and lubricate it at the same time.
I think I'll buy or try to make this thing https://www.aliexpress.com/i/1005001450711323.html

I made something similar out of good quality 5mm plywood.

Don't forget to heat the hub. I can almost guarantee that you won't be able to open yours without it.

 

[Sturmey]

It won't hurt to carry out a quick service/inspection if you have the time and inclination to do so. Even with new hubs I have added extra grease simly because some have very little to start with.

Any hub with a six screw face plate is far easier to open then a hidden fine screw one , it all depends if one has a leaverage bar to open in the first place or has to make one up.

What would you recommend to lubricate the roller clutch?. Grease can dry out and get sticky. There has been reports of roller clutches in some middrives slipping after over greasing. I have seen freewheels sticking from grease drying out.
I suppose a second question is does anyone check the wheel bearings (by removing one of the plastic dust bearing seal ) or try repacking the bearings with grease during inspection?

 

[Nealh]

I think it was my BPM that didn't have a fully contained sealed clutch , one side had three springs and seperate balls acting as the clutch sprag latch.

 

[sarac]

Problem solved! I finally came across this article and opened the hub motor using a vice.

Cute Q100CST Smaller 42mm Flange Ver Open wt Vice Disc Rotor

I opened up my Cute 100 Q100CST to figure out the number of pole pairs so I could use it with the hall sensors properly with the ebikes.ca Phaserunner controller. This is the newer Black 42mm flange to flange version of this motor. There was a previous version of this out before this that was a...

endless-sphere.com

I preheated the hub a bit with a burner, thanks for the advice.
The problem was that the three small rollers, which block in one direction, fell out of its place.