What causes this knocking?

[sandman81]

That sproket no good. Like i said, if no money just change the sproket then go from there.

[White97Banshee]

Got a new Primary Drive 41t rear sprocket coming from RMATV. Thanks guys for all your help!

[AKheathen]

yah, that sprocket went from waved, to skipping over. the problem with running that chain is that i gaurantee the sprocket has streatched it out, and as you put force on it, the streatched chain will only put force on 1 roller at a time and once again wear down the sprocket fast. the best thing that would happen is a chain break. i baught my chain on ebay for like $30 shipped. it's a race driven and has high tesil strength. so far, it has performed awesome over the past year, which is far better than i expected. check your swingarm bearings, too. grab the rear grab and jerk it side to side to see play in the pivot bearings

[White97Banshee]

Maybe I'll have to just bite it and get a new chain as well. How many links should I get for a 13/41 setup or just stock length in general? And I don't really know much about chains other than there's o-ring and non o-ring, and x-ring chains? What's a good one for dune riding?

[zachmw]

mine does the same thing in tree shots. i found sand being packed between the sprocket and chain causing it to skip. id bet thats what you got going on.

[bansheesandrider]

Maybe I'll have to just bite it and get a new chain as well. How many links should I get for a 13/41 setup or just stock length in general? And I don't really know much about chains other than there's o-ring and non o-ring, and x-ring chains? What's a good one for dune riding?

I recomend DID X ring chain, it is a decent chain for what it costs if it is properly cared for. I have never had a problem with one. For your gearing with a stock swingarm it should be around 102 or 104 links long.

[bbcmudtruck]

+1 for checking your axle bearings. It could be pulling the axle sideways and binding on the sprocket.