I bought a bike from GI Joes and the bike section. There are several mechanics and I happened to run into one of the ones who was not as smart. I tried to get a new chain and he told me not to get a chain unless its rusted. Are you kidding me if my chain doesn't get into gear easily and its lubricated isn't that time for a new chain? Its been 6 months and about 2000 miles. Should I just have a specialty bike shop install it in front of me so I know how?