520 chain is plenty tuff, my LT500 runs one, and with the load it carrys<--me, and its putting out over 65 hp and its 5 years old, they hold up well, I hate to say it the money to save the chain is the money you spend on the gearing dont go cheap.

 

becuase I was thinking on maybe putting my ds650 on a diet and go to the 520 and get the hubs from mr. HP