Zero motor bearing replacement

[RobG]

I just replaced the motor bearings in my 2014 S, it uses the ZF75-7 motor.
I made a completely non-magnetic assembly & dissassembly jig for the task.
I fabricated it in a way that it can be flat packed & posted if anyone else needs to borrow it.
I might also be able to modify it for other motors if they are not much larger, e.g. the FX.

[coulomb]

Wow, that's really intriguing. Can you post a few paragraphs on the basic process? I've never done bearings, and am curious about how it's done, especially with what I assume is a permanent magnet motor, notoriously difficult and dangerous to work with (if you don't know what you're doing, of course).

[jonescg]

I built a similar, and substantially crappier rig for pulling the shaft out of an Agni DC motor.
Solid work

[RobG]

I didn't take any photos of the dismantling, it only took about an hour as I had pre-made all the tools.
The main issue is not to let the magnetic rotor get pulled back into the stator. Once clear of the housing, put a plastic sheet over the housing opening (for dust) follwed by a bit of wood.
Dismantle in a clean room, not your old workshop with lots of metal dust around.

The following Youtube video gives the general idea
https://www.youtube.com/watch?v=hfxcc-LkrBw&t=479s

I made collars for bearing pulling & pushing, including a brass cup to go over the rear of the shaft to protect the shaft encoder magnet when using a 3 legged bearing puller.
There was NO HAMMERING involved.
I also made a swing arm bearing pusher/puller as these had also failed by 34,000 km.
The motor & swing arm deep groove ball bearings are a bit weak for the task. I replaced with top quality Timken.

[stEVeF]

Hi All,
I'm possibly heading down this path as well but wanted to run this video/noise past people who may have heard it before and identify it.
It's not the screeching noise I've heard on other videos of 75-7R bearing failures, but I'm hoping it's just that I've caught it early.
https://youtu.be/-1DmSODfJlM
The bike is a 2018 DSR which has just clocked over 40,000 kms. I've always maintained the belt tension within specs using the Gates Carbon Drive app but I've done quite a bit of heavy duty riding (over the Vic Alps a few times, the Upper Murray to Sydney, any mountain I can find basically!).
Any thoughts on the noise would be appreciated. I've called Peter Stevens Dandenong and as it's Xmas/New Year, the earliest they can look at it is 3 weeks out. This is my primary mode of transport so I can't really afford a lot of downtime.
Thanks,
Steve

[jonescg]

I still haven't recieved a copy of the owner's manual from Savage MC, so I don't know what the maintenance schedule is for belt tension. I've put 3000 km on it from the day I rode out of the shop.

[Godoh]

It may be a lot easier to just leave the rotor in place. Just take one end plate off, change the bearing, replace the end plate.
Then do the same on the other end. That way there is no problems with trying to remove and refit the rotor.
I have done that many times on electric motors. On very large machines it is much easier than using a crane to remove the rotor just to change bearings
Pete

[stEVeF]

I ended up taking the motor out myself and taking it to an electric rewinder who had the tools and skillz I lacked. A two-day turnaround and I reinstalled the motor and I’m back in action, ready for another epic ride to the Off Grid Living Festival in Chiltern. There was a very helpful procedure posted to the Zero Owners FB page and they also now have the legacy service manuals online supporting the right-to-repair.

[jonescg]

I ended up taking the motor out myself and taking it to an electric rewinder who had the tools and skillz I lacked. A two-day turnaround and I reinstalled the motor and I’m back in action, ready for another epic ride to the Off Grid Living Festival in Chiltern. There was a very helpful procedure posted to the Zero Owners FB page and they also now have the legacy service manuals online supporting the right-to-repair.

This is great news. If not for communities like ours, and the broader DIY movement in general, we'd be stuffed.