Chain keeps coming loose!
 

I'm having an issue with my chain. I'll get everything all tightened down, make sure the chains not too tight so when I sit on it, and when Im riding off road and the shock is flexing it has a little play in it. But when I am done riding, its always waaay loose.

After about 20 mins or so of riding itll get so lose the chain will come off the back sprocket, and I'm worried it'll get caught up in the casing somehow or something like that and really mess the bike up bad.

I am hoping you guys can see something in the video that isn't right, or know of a way to fix this. Thanks in advance guys! :thanks:

You can check out the video here, http://videobam.com/mLXlZ

Your frame has little hash marks at the axle holes to gauge where you tighten down the axle nuts and chain tensioners. They should match on both sides of the bike to make your wheel straight. After you adjust the chain tensioners and then tighten down the axle nuts mark your frame and tensioners with a pen or pencil or chalk or marker or anything. Take the bike for a good ride. If after the ride the chain has loosened check the marks on the frame you made to see if the axle has slipped from where you have tightened it down. If it did add a couple of these under each axle nut.

Edit: Add the lock washers under each chain tensioner so the washer is between the tensioner and the frame.


Edit Again: My bike has no lock washers and the axle has never slipped. Are you sure you are tightening the bolt down enough? The axle nuts have to be pretty snug. Do you own a torque wrench?



http://i59.tinypic.com/wqxy5t.jpg





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And I think your spacers are good. And get a new tire quick.


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Kneel behind the bike a few feet back. Look down the sightline of the chain. If it is going straight to the engine sprocket then your spacers are good. If the chain is offset at all then something is wrong.


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Ill check the marks tomorrow and see how much they move. It could be that I am not wrenching them down enough, Im just using a ratchet and box wrench, but I havent really been cranking down on it too hard, just tight enough. Someone told me that they weren't supposed to be torqued down real hard. Obviously they were full of it lol. And yea, my tire is baaad.

In addition to the excellent comments so far, does the nut feel like it is tightening up properly? If not, perhaps the threads are stripped.

Had the same issue with the boys pit bike...
totaly a design f_ _ _ up... the swing arm pivot is
to low... on a real motor bike the chain gets tighter
as the rear wheell moves up but on these Chinese
things it gets loser.. So you have to set the chain tight
I put nylon disc each side of the rear sprocket to stop
the chain de-railing.. made them 30mm bigger dia than
the sprocket...
But the ultimate cure was to buy the boy a Honda CRF150...

Ps... the chain took out 2 ignition units & one side case before we sorted it...