I ran into a friend of mine in the park today, and when I complimented him on his nice bike, he told me he was going to get rid of it. After looking shocked and awfully sad, I noticed the middle ring was broken and seemed to be missing a whole inch of teeth.
I told him it would be a shame to get rid of an otherwise perfectly good bike, everything else works fine, and I offered to fix it for him. So, my question is:
Should I replace the middle ring only, or put a new set on it?