ks16s ball bearings replacement

[Rotator]

Has anybody replaced the KS ball bearings?

I think that my KS16S bearings are now not as smooth as new.  Moving the wheel with my hand I can feel some roughness sometimes.

May be it's time to replace them, and I suppose this will be not an easy work...

[The Fat Unicyclist]

Perhaps replace them for KS-16X ball bearings... You get a set free with every KS-16X.   

[Rotator]

I'll try to replace them this week and I'll post information about the process.

[Rotator]

I have replaced the ball bearings of my ks16s. It is not an easy job.

Fist of all, you need to dissasembly the wheel and take the motor apart. Because I am changing the tire, I haved dismounted it, but I think this is not needed.

Next thing you need is to release the pedals from the hub. Be warned: the screws are very, very tight. You will need a good strong tools.

With the pedals removed, a thick washers in both sides are now free. Be carefull: do not loose them.

Now you can take the motor apart. First of all, remove all the twelve screws. Again: do not loose them.

You can now open the motor. The cover is now free so you can raise it (be carefull with the cables and connectors). Note that there is a thin washer in the hub (if it is not glued to the bearing)

The first bearing is in the cover. You can replace it now. In order to do that, you will need a way to push the ball bearing out of the cover. I use a big screw with a head that can go through the cover hole, but no so thin to go through the ball bearing hole, so it can push the bearing out to the inside part of the cover. On the other side of the screw, you need something to get the screw support against the cover, with a hole big enough to allow the ball bearing to get out. I have used a big circular saw drill tool. All you need to do is to tighten the screw. With each turn, you will push the ball bearing, and it will be out soon.

Now you must clean the ball bearing housing of the motor cover. And put some grease once clean. And grease the new ball bearing too. To put the new bearing you can use the screw pushing it now in the other way. I have tried this method four of five times, but the bearing always tended to bend someway, so finally I have used a hammer with a very flat, thick metal platform, to fit it evenly.

Now, in order to access the other ball bearing, you will need to remove the inner part of the motor (hub and coils). Because there are magnets all around, there is a bit tricky job. I have put a piece of wood over the floor, and then I have hit it with the bottom part of the hub, so the inner part of the motor can go up and get out of the motor housing. Be carefull with your fingers. Remember that there are a lot of magnets and the inside part of the motor can go up and down very quickly and can catch your fingers in between. To help the process, I have used three cable wires (as ropes) holding three of the motor spokes, and another person grabbing the ropes and pulling up. Probably you will needs several hits. The inside part of the motor will be released eventually and you will gain access to the other bearing. Be realized that there are another thin washer.

To replace this ball bearing you can use the same method used with the motor cover.

Now, to put the inner part of the motor again in its housing (do not forget the thin washer), a person can hold it from above (with the ropes) near the housing, and you can align the bottom part of the hub with the hole of the recently installed ball bearing. Not so easy, since the magnets are there trying to unbalance the thing, and trying to catch your fingers at the same time. A few tries and you will get it.

Time to put the cover again (remember this side thin washer) and their screws. I have greased the cover edge all around before (where the edge contacts the motor housing), to prevent the water getting inside.

Finally, put the thick washers and the pedals and thats all.

I have took some picture and you have them here: https://photos.app.goo.gl/JDQGSzRwmBUXJpet7

If your DIY skills are not very good, try to not replace the ball bearings unless it is absolutely essential.

 

 

[Joker10]

Thanks for sharing.  So the bearings have to be removed towards the motor right?

[Rotator]

Right!

[Joker10]

Thanks. 

[null]

Thanks for sharing the process, can be useful for others.

I’d be curious to know at which mileage it would be recommended to do. AFAIK bearings can run for very long, but in EUCs there is quite a bit of pressure and shocks on them

Did the ones you removed feel any older from the new ones? I find my 16s to not be so smooth, but it is probably mostly the motor.

[esaj]

On 6/27/2019 at 2:07 PM, Mimolette said:

I’d be curious to know at which mileage it would be recommended to do. AFAIK bearings can run for very long, but in EUCs there is quite a bit of pressure and shocks on them

Also interested in the mileage, I haven't really noticed anything yet, but my S has several thousands of kilometers (how much in fact, I don't even know, I haven't used any apps in a long while) behind it, and I might face this issue at some point.

[Flying W]

Also interested in the milage,  I have a little over 1400 miles on mine and everything still feels fine. 

Were your old bearings bad enough for the wheel to have some play in it side to side? 

[Rywokast]

im more interested in why you would need to change the bearings.. its a completely enclosed environment and should be able to run for tens of thousands of kilometres.. perhaps there was some sort of damage sustained at one point in time? i have heard of people with over 30,000 on a single motor, yet this is the first time ever hearing about a problem with the bearings. if i was having a lot of issues and had a ridiculous mileage on my motor i would probably just replace it at that point since you can get a good motor for around 300 USD.. however obviously it could be an older motor that is no longer sold where the new ones are incompatible with your EUC in which case replacing parts is a good option.. interesting nonetheless, did you find any issues or obvious signs of wear when you opened the motor? only thing ive ever heard previously was rust from a lot of water ingress over time

[Rotator]

@Flying W , @esaj, @Mimolette:

The KS16S ball bearings were replaced at 10,000 kms of use aprox.

@Rywokast:

Rotating the wheel by hand with the euc powered off, it showed some kind of roughness. Very little, but anyway, it was not as smooth as new, so I decided to replace them before to have any issue.

 

I am about 72kg and I try to drive the wheel in a gentile way, avoiding bumps and jumps over the curb.

May be the stocks ball bearings would last another 10,000 kms more, I will never know.

Anyway, I can say that the replaced bearings were a little worn. Not very much, but the looseness was noticeable moving the inner ring with my fingers, especially comparing them with the new ones, which were entirely tight.

My Ninebot One are 10,000 kms as well, and its bearings appears to be better than the ks16s ones. Better quality?  I don't know...

I have replaced them with bearings of the SKF brand, which I know it is a quality brand.

The old ones appears to be SILNT brand. No idea about their quality.

 

[null]

Thanks for the reply @Rotator , there are quite a few grades of ball bearings, SKF being upper tier indeed.

Ill seriously consider changing those of my 16s when going past 5k km, might as well switch to better quality sooner than later.

thanks again, useful for everyone’s reference.

[Flying W]

@rotador thanks for the info!