yeh time for new, Average is right around 10 to 15 k for chain sets. Always change chains and sprockets together. They wear alike and an old chain will wreck a new sprocket and vice versa. Cause is just normal wear. Gotta realize the force that those components are under. Most likely the vortex sprocket is aluminum. It is the easiest material to cnc cut and it is the lightest. After you install the new set put a staight edge up against the chain and make sure you have good contact all along the straight edge. chains can tolerate a very little amount of mis-alignment but not much. IF you continue to ride take it easy. Teeth will come off like a domino effect if you beat on it. Eventually the chain will slip or come off. Very bad stuff, if you are lucky the chain will split and just roll off on the road. if you are unfortunate it will get piled into the back of your motor case and punch a hole.