Bought my son a Coolster 125, after two weeks of ownership and light riding and I have noticed both rear wheels already appear to be warped. Im not sure if its the rubber or the rim. has anyone else come across this issue?

Does anyone know of aftermarket wheels/tires that would fit that are tougher maybe a little bigger?

Video of wobble
YouTube - Coolster 125 ATV

Note: (It appears that the axel is also out of wack in the video but its actually the sheath that goes over the axel that was off slightly)

 

Welcome to the forums.

Knowing the types of material and quality control (ha!) of some chinese models, a bent wheel or two could have come from the factory. I don't know the bolt pattern for your model but I'll bet someone here does. From there you could see if a Honda or Yamaha (two most likely) wheel would fit.

 

Or is it the axle spline / hub free play? If you raise up the quad rear wheels, grab the wheel, and try to rock it side to side, does the wheel hub wiggle on the axle?

 

No, both wheels are solidly attached to the axel.

 

Is the bead of the tire seated against the rim? The tires need about 10psi. I have looked at some replacment tires for my son's Taotao 125D. They should be 16x8x7. Take a look at these:
AMS Swamp Fox 16x8x7 Tire | TV00980 | J&P Cycles

Also, in the video, I noticed your chain needs tightening which is not uncommon as the chain will stretch.

 

Alot of them do that from the factory. (Ive built/serviced tons of coolsters at our shop)

 

when you were holding the camera still, i could get a reference point and noticed that the axle is slightly bent. it appears to be causing the wobble from the point of bearing anchor/attachment. fairly cheap fix to replace the axle. but i don't see where it's hurting anything right now. if you're unsure of what i was looking at, put it back on jacks/blocks and let it run as you did in the video. sit behind it and watch the axle. you'll see it do a somewhat elliptical "orbit"/wobble from where it attaches to the frame. if you bought used, it's possible someone jumped it and it bent that away. anyways, that's my 2 cents...........

 

I bought it brand new

That wobble you see on the axel is actually a metal sheath that goes over the axel that can get off center. I removed the sheaths on both sides and noted that the axel is perfectly straight.

 

All the tires have good psi

Thanks for the recomendation on the tires I will check those out.

As far as the chain I noticed that when I initially assembled the ATV however when my son sits on it the chain is taught.

 

I contacted the company I bought the ATV from and they are submitting a claim to Coolster on my behalf. They are supposed to be getting back to me.

I still think the rims are made of cheap metal and just got bent. We go riding a couple times a week and my son doesn’t even notice, so it really isn’t too big of a deal.

I just hoped the cheap little quad would last at least a little while.

P.S.
It now makes a horrible metal on metal clanking noise when starting it sometimes.

Oh well, the next one will be a Honda