KS18XL Stator slippage/problem?

[Paul A]

Does anyone else have this problem?

 

KS18xl started to shudder/vibrate/tremble very violently when braking.

Thought maybe it was stator slippage problem like the S22.

Opened wheel and there is a gap of around 1.5 - 2 mm around about one third of the wheel, between the magnets, on either side of the hall sensor.

Can visibly see through the gap, and insert a toothpick in the space.

The other two thirds of the wheel have no gap at all.

 

Could this gap be causing the very violent shuddering?

If so, is there a repair/solution?

Thanks.

 

 

[supercurio]

It is normal to have a gap between the stator and the magnets, otherwise there would be friction between them.
Since the side covers are missing, the stator and rim are now misaligned: this is why you observe an uneven gap.

Edited December 8, 2022 by supercurio

[wehey]

My 16X did this. It was a cracked inner shell around the pedal hangers 

[Paul A]

@supercurio

Could a faulty hall sensor be causing the violent shuddering/vibrations upon braking?

 

Can't really tell if slippage has occurred.

Would it be advisable to just proceed to have the motor pinned, regardless?

Could just send the RevRide YouTube video to a CNC milling workshop, to fully explain what is required.

Thanks in advance for advice.

[Chriull]

2 hours ago, wehey said:

My 16X did this. It was a cracked inner shell around the pedal hangers 

+1 - my brothers ks18xl did the same once his shell had a crack near the pedal hangers.

 

36 minutes ago, Paul A said:

Could a faulty hall sensor be causing the violent shuddering/vibrations upon braking?

But a faulty sensor would imo more likely not lead to shuddering but total failure.

Shuddering is more a sign of something's beeing loose...

Edited December 9, 2022 by Chriull

[Mark Frey]

I had mine do this a low speed a few times a long time ago. Once when coming off mountain and once when on road going medium and was a odd like what seemed electrical that wasn’t a cut out obviously but shuddering and it would then go away. And I had it happen a few more times and I assumed it was a out of balance tilt back or not have it calibrated since it happened coming off the hill with much decompression and I did recalibrate it and to be honest I have never had it happen again and the wheel is great. It is nothing like a cutout but is this like grinding that seems the motor is doing an reverse type oscillation as if trying to slow down and almost sounds like a grinding but I feel it is purely an electrical fluttering . Yea I was trying to write about this awhile ago but wasnt signed in. I had disconnected my lift switch a long time ago. But this I think has something to do with being totally not calibrated since I did calibrate it and have never seen this again. Yea am not sure though.it is a great wheel still and yea that was weird. 

[Mark Frey]

I thought it had something to do with static electricity buildup at one time but is true the pedals were calibrated way back and not level and this I think was the reason..that the hall sensor was at the limit or something and trying to do its thing but was too far out of level. Not sure but I thought this was it.

[Mark Frey]

I thought it was static electricity arcing in some way . It was like the motor made a different noise and a vibration and made me spooked and then it was working again. It was just this one time and another time after I had climbed a very long steep mountain and the ride down it did that again a few times and I got worried. But yea I thought to calibrate it with the app and never have seen this again and have forgot about it and I ride it everyday still just thrash it . This was a long time ago.

[Mark Frey]

There was someone who wrote about this before and it might of been you but they never had the wheel apart but were just asking about the reason for the vibration shuddering . I had wanted to reply but couldn’t get logged in to forum. But yea I was really interested in this phenomena exactly since mine did it. Has nothing to do with pinning the stator. It is a mystery . Was wondering if yours was doing that chronically or if did occur on occasion. Mine never did it again and has been over a year and a half or more. And I ride it a lot

[Tawpie]

@Paul A the green wire in the top photo is pulled taut, if we assume your stator didn't slip you still want to reposition the zip ties on the cable bundle so that the green wire has some slack (aka stress relief)... and give the wire/solder connection a look at 10x (jewelers loupe) to ensure that none of the wire strands are broken. I think something may have slipped or your motor cable got yanked, I'd be surprised to see that kind of workmanship in any motor... it shouldn't be that way.

I don't know what the green wire is for, it could be the motor temperature wire (on S22 the motor temperature wire is black) but odds are it's for one of the three hall sensors.

While it's impossible for the wheel to operate at all if any hall sensor connection is completely broken, having an intermittent connection to a hall sensor (from for example, broken strands) could confuse the controller as to where exactly the wheel is in its rotation, and that conceivably could lead to shuddering.

I'd get in touch with your reseller and send them your pictures. Either way, give that green wire some stress relief.

Edited December 31, 2022 by Tawpie

[Mark Frey]

How do you explain that mine has never had this issue again and is going on almost a couple  years ago I felt the same thing a couple of times but it then went away for no reason. I just kept riding and calibrated it and just totally forgot about it till did read this post. It remains a mystery and my wheel is running perfect. I thought it had developed static electricity from rolling at first but later it is true i recalibrated it since pedals were way off level. I was wondering how often yours actually was doing this. And did it run normal then ? And if so how long did it run normal before doing it again and in what conditions ? Yea I know it is a irritating like grinding ratcheting as if yea ..a sensor is causing the electricity to oscillate between two magnets or something.. not totally sure but it is amazing I never had that again to this day.