Ok
Although I don’t claim to be a “chain” expert…I have destroyed quite a few…and by “destroyed” I mean when we sent them to RK in Japan for evaluation they simply were amazed at what we had done to them…. So first off I wanna say, “buy the best chain you can afford” and if you cant afford it, save your money and them buy it…. Really, there is a huge difference in quality of chain and the performance between them…. Go to your local dealer and have them show you a cheep chain and a pricey one… compare the thickness of the link plates, compare the pin size and the roller themselves, you will see a huge difference… As for the “O” ring and non “O”ring…we tried no “O” before, that’s when we were stupid… not saying we are smart now but we believed in the “less drag” theory…. no “O” always failed way faster than the “O”…the reason is that the link plates rub on each other every time it makes a turn around a sprocket and creates a tremendous amount of heat, so much heat that the chain turns purple… the “O” ring spaces the link plates apart so that they don’t rub…and after the chain warms up the “O” rings don’t drag any more… if this was a 50cc bike I would say no “O” but at 500cc you need "O"…. We ran the best MX chain RK makes on the Aprilia that Dusty set the 250PP record with…the fastest he ever went was WITH the “O” ring chain and PJ1 lube (in the blue can) stay away from that chain wax crap…. Stay away from high solvent cleaners like WD40 as it gets trapped between the rollers and pins…if you need to clean the chain of excess lube test the cleaner on your fingers first, the solvent should evaporate fast or don’t use it, then lube the livin snot out it….. I have been sponsored by RK for 23 years but during my chain problem years we tried other brands…. they failed just as quickly…. Hopefully we have our chain problems past us... RK was helpful and supportive so my suggestion would be RK 520MXZ4…it is the lightest MX chain, Biggest pin dia, thickest plates, and should last you a season, and don’t buy the GB unless your into that gold plated bling bling extra charge…. good luck
Kent