Im planning on purchasing a new 520 chain and sprockets. My first question is: why dont people use an 18 front and maybe a 47 or 48 rear? Im not sure if the front sprocket will fit but if it does, wouldn't it cut down on the stress of the chain? Second question, Moving to a 520 set Im looking for the highest tensile strength chain I can get. Im wondering what peoples experience are. Im looking at the: RK 520ZXW (9450 lbs/Ft) the EK 520ZZ or the 5203D ( both have 9400 ft/Lb tensile strength so Im not sure what the real differences are. ( List something else if you think its better please ) Finally I know there are plenty of front and rear sprockets. Im trying to find out what everyone's wear has been like with any given brand. Thanks for the help!!!