Bearing Replacement

[Adamsavage79]

Is there a practical way to replace the bearings on the Magic Pie 5 motor ? Looking for a video or some sort of schematic on how to do this.

[Bikemad]

To replace the bearings you will need to remove both side covers from the motor, but it is better to do one side at a time so that the stator and axle are properly supported inside the hub.

The bearing on the MP4 and MP5 are exactly the same size as the MPIII bearings shown below:



The freewheel side cover can be removed complete with the freewheel still attached if you don't have a freewheel removal tool, but it might make it more difficult to drift the bearing from the cover with the freewheel still in place.
If you are using a slide hammer and bearing puller kit you shouldn't have to remove the freewheel unit anyway.

You can remove the brake disc and cooling fan assembly from the side cover as a single item, so don't bother removing the disc from the cooling fan assembly.

The controller should not need to be removed from the stator housing as the cover and bearing should slide over it.

I've never had to remove the large bearing from the side cover, but I suspect that a suitable bearing puller or a special drift may be needed to extract it, probably combined with some penetrating oil and a bit of heat.
If the bearing is really tight inside the cover, a manual or hydraulic press may be required. 

Check out this post for more details.

Alan
 

[Adamsavage79]

That's a massive bearing! That's insane! That large bearing is on the wire side, so the wires should not get in the way ?

[Adamsavage79]

UPDATE: I tried go local for the bearings, but they wanted too much for the large bearing. $250 plus! I went with CDN website instead. These are the ones I ordered, per the picture above. I ended up paying extra for Fed Ex, because with Canada Post, it could be a month or more before it shows up, so that isn't an option for me.

https://www.bearingscanada.com/ProductDetails.asp?ProductCode=6302-2RSJ-EM-Quality-15x42x13

https://www.bearingscanada.com/ProductDetails.asp?ProductCode=6917ZZ-Shielded-85x120x18-Ball

[Bikemad]

I tried go local for the bearings, but they wanted too much for the large bearing. $250 plus! I went with CDN website instead.

That's very cheap compared to the food grade bearing at a mere $1,120.44 each.

Is there a particular reason why you opted for the metal shielded version of the large bearing instead of the rubber sealed version?

Alan
 

[Adamsavage79]

That would be by mistake. I didn't catch that. I should see if I can change my order.

[Adamsavage79]

I was able to switch out the bearing for the rubber one, so that's a good thing.

[Adamsavage79]

Hi Alan, I'm expecting my bearings any day now. I was just going over instructions how to replace the bearings. The freewheel side has TWO bearings, and the smaller one fits inside of the larger one ? The controller side has a large bearing, that looks like you can just repack with grease ? I'm wondering if I can get away with repacking, vs removing the bearings. I don't have a Metal drift or a bearing puller, let alone a slide hammer.

[Bikemad]

I have not come across a Magic Pie 5 with dual bearing on the freewheel side, unless GM have modified them to take a cassette like the Cassette version of the Magic Pie Edge.

This is what the single axle bearing on the freewheel side cover Of the Magic Pie 5 looks like when viewed from inside:



Yours shouldn't have the end of the axle poking out of the centre of the bearing like mine does in the above photo, unless you have also placed the cover backwards onto the axle to take the photo.

Are you able to post a picture of the "TWO bearings" on the freewheel side of your MP5?

With regards to repacking the large bearing with grease, this should be relatively easy to achieve if it has the rubber seals that can usually be prised out quite easily.
However, if it has the metal shields, these can be more difficult to remove without damaging the thin metal shields, another reason for using the rubber sealed bearings. 

Alan
 

[Adamsavage79]

Soon as I get my bearings, and take a look @ the motor. I believe I have something similar to a metal drift, but mine have more pointy end. I believe Ottawa Fastener would have one at worse case scenario. Best case is everything is rubber sealed, and I have two spare bearings for just in case sort of thing. I like to have spare parts, so not at all a loose.

[Adamsavage79]

I got both bearings today, but I feel like I'm missing details. It's clear one bearing will not fit inside the other, so there clearly something else between them. Could I get a break down of what I would be looking @ when I remove the cover ?

[Bikemad]

If you remove the freewheel side cover you will see this:



And this is a close up of the small bearing inside the freewheel side cover:



This is where the small bearing locates onto the axle:



If you remove the controller side cover you will see this:



And this is what the inside of the controller side cover looks like:



The stator/axle assembly (and possibly some spacer shims on the freewheel side) is what goes between the two axle bearings:



The large bearing fits over the outer surface of the controller housing.

Hopefully it will all will become more obvious when you remove the covers.

Alan
 

[Adamsavage79]

Ok so the small bearing on the freewheel side, and the large one is on the controller side. What is throwing me off, is the extra "rings" per say, but I have a better understanding now. I will charge the batter up tonight, then bring it down into living area, and possibly try and take covers off ? I'm just nervous doing this, as I'm worried it will be difficult and or complicated. There is also the worry I could dmg something as well. I COULD get my bike mechanic to do it, when he rebuilds my wheel. He might have more tools and such. I definitely want to try and take the covers off and have a peek inside, then go from there. If I don't feel comfortable doing it, I will leave it alone. The bike still fully usable, it's just very loud the wheel and it's annoying.

[Adamsavage79]

I found a good video that shows how the motor side cover is removed.

https://www.youtube.com/watch?v=oNp_qAeBH9Y&t=577s

[Adamsavage79]

I finally got around to replacing the bearings. I'm halfway done and I don't think I can go further. I can't remove the controller, as the screws are rusted in pretty good. I would strip the head trying to get it out, which isn't a big deal, as I have a screw extractor. However, if they won't budge, there is no point and trying that either. I was able to get one screw out, so I can take that and get a replacement. All I did for the freewheel side was remove the screws, and gently pry it open with a flat head. Then slide the spacers off, and then I was to simply slide the cover off. With a bit of fiddling around, I got the bearing out. I think I just stuck my finger in and it came out. The replacement one took little more effort. I don't have a rubber hammer, so I folded up some rubber and gently taped the bearing into place.

As for the otherside. It's not coming out. I whacked it pretty good with a piece of wood and hammer, and it moved outwards little bit, but not enough to get my flat in. I also had the side effect of it sliding down. I noticed when I tried to put the screws back in, they were not lined up. Thankfully, I knew which direction I needed to go, as I marked the wheel with a permanent marker. I grabbed a microfiber cloth and tried to turn the cover back, but went the wrong direction. So it ended up sliding in the wrong direction. I was able to turn it mostly back. I then took my flat head and gently tapped on the heatsink of the controller, until everything lined up.

I put everything back on the bike, gave it a quick test spin to make sure I didn't damaged the wires inside, and everything seems to be ok.  From the looks of it, the large bearing is rubber sealed ? It might possible to access the seal and bearings, from the freewheel side, without needing to remove it.

EDIT: Couldn't I just tap out the cover from the freewheel side ? Gently tap at it with a piece of wood or something, so as to not damage the inside of the cover ??