I don't know how much it matters on a bike pumping out like 50 some horsepower. Just get a middle of road chain and you should be fine. You have to remember that when some of those sites say a chain is rated for 600cc or something, they could be talking about a 120hp R6, so I don't know much those ratings matter on an older bike. O-ring is better and will last longer unless you're a freak about cleaning your non o-ring chain..