stator/chain problem

[lochie125]

hey guys,
on my last three rides of been on i have had my chain come off go through the chain guard and into the stator snapping off the magnet
first time we thought it was just because the chain was loose and came off, second time the chain tensioners where all buckled so the wheel just kept on sliding foward so the chain came off, we fixed the bike and replaced the tensioner, so then i went for a ride yesterday at my local track thinking everything would be alright and nothing would happen i lasted a quater of a lap so about 45 seconds of ride time and it happened again.
i dont know what it is and am kind of getting over it happening and want it fixed
i was womdering if anyone had any suggestions or its happened to them and they know what the problem is
thanks

 

[rotn50]

do you have a chain guide on the swingarm near the rear sprocket, hold the seat and firmly grab the rear wheel and push the tyre side to side is there movement in the swingarm bearings, is the rear axle bent, when everything is right and ready to ride did you get back bout 5 metres and visually see that the chain is perfectly straight and not out of alignment with the front sprocket.

 

[Phil67]

wheel bearings gone?

 

[timeeh]

check that you have lock-nuts on the tensioners as well.

 

[lochie125]

do you have a chain guide on the swingarm near the rear sprocket, hold the seat and firmly grab the rear wheel and push the tyre side to side is there movement in the swingarm bearings, is the rear axle bent, when everything is right and ready to ride did you get back bout 5 metres and visually see that the chain is perfectly straight and not out of alignment with the front sprocket.

i forgot to mention i replaced the rear axel before sunday because it was bent, there is only a tiny bit of movement in the wheel but i havent checked the swingarm ill check that tomorrow

 

[lochie125]

check that you have lock-nuts on the tensioners as well.

yeh they have lock nut which i tightened up the chain was all fine so ill check swingarm bearing's and i was also thinking could it be warn sprockets?

 

[rotn50]

yeh they have lock nut which i tightened up the chain was all fine so ill check swingarm bearing's and i was also thinking could it be warn sprockets?

Worn sprockets can cause a chain to come off, the sprocket will usually be arched thru stretch as opposed to pointed when new