i was riding my bike, and noticed a clicking sound. one of the little spinners in my derailleur broke off right outside my house (i found it walking home). i went down my half mile hill and about another half mile before my bike stopped working, pedals had no resistance. the chain was also REALLY loose. some guy came outside his house, saw me struggling, and told me what was up. i decided to get a new derailleur since it looks all buss-up anyways. i had a shimano, so im looking for shimanos on ebay and i will look into my local bike shop. any recommendations on what to do?
also, i assume i have to get one with 7 speeds since mine is a 21 spd bike.
ok i got a shimano derailleur. the hard parts are
A) how do i position the derailleur (its a hook on), like how much do i rotate it
B) i can't break the chain to run it through. i bought the chain separating tool but its too damn tight