Problem with Free wheel

[JGH]

Hi,<br />
I have a Trek 4500 Mountain Bike, recently the chain broke which i replaced without any problems after watching your tutorials. However since then when i select the lowest gear on rear derailer the free wheel seems to rub against the cassette and makes a clicking sound, i tried adjusting the screw (not H or L screw, the other one) but it doesn't make a difference!<br />
Any ideas?<br />
Thanks.

[DaveM]

By "free wheel" I think you mean the two small "jockey wheels" on the derailleur? It sounds like you have a chain length issue. You generally have to take a few links out of a new chain before you put it on.
The way I size a chain is to put it on the two smallest (f & r) chainrings. Then pull the ends of the chain together just far enough so it doesn't rub on the bottom of the derailleur anymore and just hits the jockey wheels. If you join it at that point, you should still be able to go into the two largest chainrings without "excessively" pulling the rear derailleur.
Sheldon Brown has a different (and probably better) system: http://sheldonbrown.com/derailer-adjustment.html#chain
Final adjustment is then made with the thrid screw you were playing with