according to this http://blackmountaincycles.blogspot....hain-care.html a properly cared for chain will last longer and if you replace the chain when it needs to be replaced the cassette can last a very long time.

I have been trying the progold chain lube he mentions but it has only been a month i clean my chain after every ride and lube it every few rides and wipe off the excess. i hope it works for me.