Using a kmc z610 and there is no frame rub, there was a lot of rubbing with the kmc cool, same problem on the old conquers, but if you use a thinner chain, which i believe is what most people use in china, (i.e. 9 speed chains for light weight) there would be no problems, i am running dual disk at the moment, the new bow has an extra gusset just behind the seat, which should make it stiffer though i would still recommend using a booster.