Chain And Sprockets

X is the latest technology , "O" ring is more than up to the same job but may not last quite as well , talking 'No' maintenance - lube here ...

 

X type all the way.

 

I'd go with either from a proven manufacturer and if you're changing sprockets get good hardened steel items, light alloy don't last 5 mins even with good lube. Don't get hung up in the pursuit for an X ring, O ring was good enough for donkey's years and they still are. Good maintenance is the key to long chain life.

 

X ring provides better seal for retaining grease and won’t cost any more. There simply isn’t any reason to fit an O-ring for comparable money.
Last O-ring chain I had was on my VFR 750. I needed regular adjustment and was pooped by 10000 miles.
X ring on my Tiger would have lasted 20K+ had I not changed it early and rarely needed adjustment. Of course, could have been coincidence but both X-ring chains on my other two bikes very rarely need adjusting, one is RK and the other is Regina.