OK, there seam to be a lot of threads on this subject so I don't think starting a new one would be a big deal. I maintain 5 dirtbikes and seam to adjusting chains and buying sets all the time. I used an o-ring chain setup a while back and can't remember if they last longer. What is the best longest lasting setup that does not require constant adjusting? My current chain on my 1999 RM250 needs adjusting after almost every ride. That's a couple hours of so. It was a cheaper chain so I guess you get what you pay for. I don't mind spending more money if it last a long time. I just got a 2007 YZ250 that will eventually need a new chain and sprockets, so I want to get the best. What should I get??? So do o-ring chains last longer and stretch less often? Are the sprockets specific to the type of chain used, o-ring vs. non o-ring? Which are very good. I seams Rental chains are not very good.