Wobbly wheel issue with my HS3540

[zooz]

Hi folks,

I have ridden my Crystalyte HS3540 for over 4000km without a problem, but recently I noticed some movement in my rear wheel at its axle. It feels wobbly, especially when riding slowly. The wheel seems to move side to side a little. So I changed the bearings of my hub motor, but the issue is still there.

I did check the spokes and they are just fine.

Any ideas what is happening with my hub motor?

Any help is much appreciated. Thanks in advance.

 

[bowlofsalad]

How do you mean you checked the spokes?

Are you certain the wheel is true in all ways? Are you very familiar with wheel building? There is more to it than tension. Take the tire off and watch the rim spin very closely and carefully. Observe it vertically and horizontally.

I would have loved to see a video of changing bearings.

 

[zooz]

Well I am no expert in wheel building, but the spokes aren't loose. The thing is that I can move the wheel side to side by my hand and I can feel that the movement is at the axle level. It feels that the whole motor shifts to one side and comes right back as I move the wheel, if that makes sense.

The wheel might not be perfectly true, but that's not my main concern right now.

 

[bowlofsalad]

Well I am no expert in wheel building, but the spokes aren't loose. The thing is that I can move the wheel side to side by my hand and I can feel that the movement is at the axle level. It feels that the whole motor shifts to one side and comes right back as I move the wheel, if that makes sense.

The wheel might not be perfectly true, but that's not my main concern right now.

Is it possible that you didn't push a bearing all the way into place somewhere? My guesses are either the wobble has to do with the spokes, maybe you got the wrong sized bearing or botched the bearing job some how.

Either way, probably the most easy thing to do would be to check the true of the rim. I don't know what could be the cause of the play in your axle for sure, I've never heard of this issue before.

 

[zooz]

Well I am no expert in wheel building, but the spokes aren't loose. The thing is that I can move the wheel side to side by my hand and I can feel that the movement is at the axle level. It feels that the whole motor shifts to one side and comes right back as I move the wheel, if that makes sense.

The wheel might not be perfectly true, but that's not my main concern right now.

Is it possible that you didn't push a bearing all the way into place somewhere? My guesses are either the wobble has to do with the spokes, maybe you got the wrong sized bearing or botched the bearing job some how.

Either way, probably the most easy thing to do would be to check the true of the rim. I don't know what could be the cause of the play in your axle for sure, I've never heard of this issue before.

I had this issue before I changed the bearings. That was the reason of changing them. I definitely got the right size of the bearings and installed them properly.

But thanks, I will double check my spokes. I have a suspicion that something else is loose, maybe on the side where the cassette is mounted.

 

[dogman dan]

Doesn't seem possible to be anything other than bearings related. Very weird problem. I think it would be pretty obvious if the problem was spokes related. Axle worn down when the bearings went bad?

 

[zooz]

Doesn't seem possible to be anything other than bearings related. Very weird problem. I think it would be pretty obvious if the problem was spokes related. Axle worn down when the bearings went bad?

It does not seem to. I had to push the bearings on when I was changing them. I guess I will have to take it apart again and double check everything.

Any recommendations on the bearings I should buy? Any good brands?

Thanks!

 

[MAGICPIE3FOCUSPOWER]

Just live with that wobble!
It's just the design.... :lol:
I have the wobble problem just from new motor

 

[Mikoby]

I agree, my wheel wobbles a bit too despite fitting 2 torque arms (which has improved it by the way) but other than being difficult to align v brakes it hasn't caused me any problems with 6 months hard riding

 

[MAGICPIE3FOCUSPOWER]

Yup I have only problem with aligning disc brakes.
O well most of 99% I use front brakes

 

[dogman dan]

If I understand this right, the wobble is the kind where you can grab the tire, and it will move back and forth, with obvious slack at the axle and cover interface.

Not the typical lopsided machining, that means your hub wobbles and you have to adjust spokes so the rim does not.

I can't say I know what bearing to recommend, but next time take the axle with you to the store if possible, and find a bearing that fits the axle tight. Damaging the bearings installing them is a possibility too. More likely is that the axle is not exactly machined so great.

 

[MAGICPIE3FOCUSPOWER]

No the motor is wobbling rim is just straight.
You can see the disc has a wobble, first I thought the disc is not 100% center.
But after installing a new disc, the problem is still exist

 

[izeman]

if i understand that correctly, you can MOVE the whole wheel a bit from one side to the other?
the only way this is possible is if the bearing seats are worn out. be it at the axle or the side cover's ones. the first time it opened the motor the bearing was a quite tight fit, but the more often i did it the more loose it became. it's only aluminium ...
what i found out when i swapped the bearings for high quality one was, that once the motor is closed (side covers installed) you can move the axel 1-2mm from one side to the other - with a 3 arm puller of course. i had to do that, because with the axle at one extreme the side covers rubbed at the windings, so i had to move the whole rotor/stator combination a bit.
btw the correct bearings are skf 6203 2RSH / 2RS / 2RSR 17x40x12mm (6203 is important - i just bought 2RSH for water and oil sealing the motor, not necessary if air cooled, and not recommended if so, as those bearings have a lot of drag)

 

[MAGICPIE3FOCUSPOWER]

Also I have replaced bearings for SKF ones when the motor was new.
Yes i think you may right, I can hear something is rubbing.
But motor is still working

So maybe it's not a bad idea to install thin washers for the bearings?

 

[izeman]

Also I have replaced bearings for SKF ones when the motor was new.
Yes i think you may right, I can hear something is rubbing.
But motor is still working

So maybe it's not a bad idea to install thin washers for the bearings?

if you hear it rubbing, then it's MOST probably the insulation of the windings that's being rubbed away. you don't want that
washers (or better shims as those very thin washers are called) would be the best way to stop the axle from moving. but on the other hand if you remove all possibility for the bearings to move you create something called "double fit" (at least this is what it's called when translated 1:1 from german *ggg*). and you don't want that, as the bearing and the covers need some air to move as it expands when it gets warm. aluminium and steel don't expand at the same rate, and if you totally remove play one part (in this case the alu covers) MAY break.
just my 2c

 

[MAGICPIE3FOCUSPOWER]

Thanks for your info
Hmmm good to know about the shims, okay I will forget this idea.
May I should open the motor when servicing

Hopefully thew version motor is better

 

[999zip999]

I have a 3525 and have a clunk when I hit the throttle. I replaced bearing and still clunk be did notice one side cover is loose and one side cover is tight before the screws installed. I think my cover is just loose when dropped over the motor. Yes just the cover and the raised ring on the inside of the cover dosn't have interfurance. No time to remount and check.

 

[amberwolf]

On my 3540, the left side cover kept loosening, until I glued the screwheads down. It would cause a wobble like the OP describes.

 

[MAGICPIE3FOCUSPOWER]

My motor covers are still tight, I check them after every some running times...
Thanks anyway for the tip 8)

 

[izeman]

I have a 3525 and have a clunk when I hit the throttle. I replaced bearing and still clunk be did notice one side cover is loose and one side cover is tight before the screws installed. I think my cover is just loose when dropped over the motor. Yes just the cover and the raised ring on the inside of the cover dosn't have interfurance. No time to remount and check.

if the bearing is loose you can use loctite 648 to glue it in. but once it's mounted it's hard to remove

 

[dogman dan]

I'm still unclear what the exact problem is. Nearly all hubmotors have some tweak, that makes a disk or the stator itself wobble down the road. The machining is not that great, the hole in the covers is more or less in the center. More or less aligned right.

But my read of this guy, is that his entire wheel has some play in it, while the axle is stationary. Not just loose spokes or a rim out of true. I think he still has a bearing fit issue or something like that.

 

[alsmith]

I changed the bearings on my 5300 and the fit for the bearings was poor. One side was the outer race, the other side was the inner race. Apart from changing the shaft and housing, or metal spraying and machining (I've never looked into this so not even sure it's possible) the only option is the anaerobic bearing fit sealants. There are several on the market, Granville Bearing Fit and Studlock, Loctite 271, S.A.S Bearing Fit and others. I'm not totally convinced of there abilities, but it's less expensive and quicker than the 'proper' way.