The derailer on my 21-speed bike looks like it's bent. It won't let the chain go onto the 3rd ring of the front derailer so, no I can't shift past the 14th speed. If I try it makes a loud sound, like it's about to rip apart the whole bike.
I am not sure whether the cable is loose or tight, but the derailer does looks bent. How can I fix or adjust this?