Hello fellow cyclists,

I recently bought a used bicycle. I learned about gear shifting on the internet and tried it today. I was in a high gear cycling before a hill, and then I immediately twisted the switches to the low gear for the hill and the bike went *CRANK* and the bike stopped. I was puzzled as to what just happened, but I continued my way up the hill in a fairly low gear.

As I rode back home, I discovered the "rear gears" were not responding, but the "front" was fine.
Later on after supper, I played around with the derailer and wheels and came to a conclusion that the rear derailer is not able to shift UP but is able to shift down (I forced the chain onto the smallest sprocket and was able to shift down no problems). I also played with the limit screws which had no affect.

Any help is appreciated, and incase if you need any pictures let me know. Thank you.