Front 36V mini motor wobble

[Phil]

Hi All,
My Front 36V mini motor has developed a lot of play around the front axle. I can wobble the whole rim sideways about 5-8mm. The outside nuts are still tight. Has anyone had this problem? Maybe a failed bearing? I can see there is also a hex nut on the inside between the fork & the hub, not sure what that's for. I'll be pulling it down to check and wondered if anyone has any ideas what to look for.

Thanks,

Phil

[MonkeyMagic]

Howdy Phil

Hmm doesn't sound like the nut should be on the inside of the fork. Does your setup look like this?



If anything, there should be a washer on the inside of the fork if you had some spacing issues. And I assume you did not install this motor initially? I hope the nut hasn't caused damage over time, and if it is the bearing it's a fairly straight forward fix so don't fret there

Maybe you can upload a picture, or send a YouTube link of what's happening?

Cheers

[Bikemad]

Phil, 5-8mm sounds like a lot of movement, and I'm guessing it could be a collapsed bearing. If the bearings themselves are not badly worn, they may be loose enough on the axle (or loose inside the housing) to produce some sideways movement at the rim.

Is the movement more noticeable at one side of the hub compared to the other?

There are different types of mini motors, but I'm not sure whether all versions have the different sized bearings that can be seen in this photo:



As Monkey already mentioned, pictures and/or videos can be very helpful when trying to diagnose a problem from afar.

Alan
 

[Andrew]

I have a nut which sits in the hub before the fork. This I how the mini motor arrived. It ensures that when mounting on the axle the motor sits centred. However, I have no hub movement. have you been doing any jumps etc that might stress the hub?

[DirtyGinge]

the nut is the tightener, keeping the cover on/axle in....

It may be worth noting if you can wobble the top left, does the bottom go left or right, this would indicate either axle horizontal or vertical movement, leading to either worn bearings or loose axle horizontally

[DirtyGinge]

oh oh oh..and check if when you wobble the wheel, see if the sideplate moves....i found GM had put bolts that were too long on my one, so the cover was loose after about 80 miles, but all cover bolts tight....

[Phil]

Thanks Guys, seems like surgery is necessary, and yes, I did install the motor, it's one of the newer minis, 3 months old.  Have done about 1200km on it. I haven't been jumping, but Australian roads are not kind to rims etc, and I have a little bit of not too serious rock hopping to do on my way to work. I did have to tighten the sideplate when I first installed, so I'll check that too. The wobble seems to go the same distance left & right. I'll post my findings, when I get a chance to operate.

Phil

[GM Canada]

Hi Phil,

I saw your email and see now you beat me to the forum

I see you have a lot of good advice to go by already. Feel free to open the motor to see if you have a failed bearing or any of the suggestions that could be the problem. Please let us know the outcome and as suggested any pictures or video would be great.

Gary

[Phil]

Well, checked out the bike this afternoon. Thankfully the fix was the simplest. The screws holding the motor case had infact become loose causing the motor to wobble in the case. If I'd bothered to check first it would have been obvious, but I had it in my head that a bearing had failed. Dirtyginge, you hit the nail on the head, think I got the same longer screws, have rectified, all good.

Thanks Guys, love your work.

Phil

[DirtyGinge]

no worries my man, happy to help

[Andrew]

time I checked the screws on mini motors

[DirtyGinge]

they are about 2mm too long...you can tell if yours are too long by looking at the thread at the end...if it looks smoothened, then the bolt is too long and is threading right at the very end.......

Hope all is well with you buddy, will meet up soon, end of bathroom is weeks away yay.... (ceiling painted, lights tomorrow, tiles next week yay yay yay...)