Originally Posted by
Scooty Puff Jr
Solid advice, but I will take this one step further and say that, "you should ALWAYS change the cassette when replacing the chain".

Not really.. I change my Chain every 500miles of my Roam. Comparing its cassette to my other bikes, I can tell that i dont see any significant wearing on its cogs. Only scratches. Take note the gears and chainring already have over 4000miles on it.
I agree, cleaning up the chain regularly helps you a lot in prolonging your chain life.