A chain catcher is a cheap and easy way to eliminate a dropped chain, which has the potential to damage a frame.

Chain Catchers
All are easy to install, and most are fastened with one bolt. The chain catcher is installed with a 2.5mm allen key and installs near the front derailleur.

Chain Catcher Install
Replace the bolt and spacer in the derailleur with what is provided, once the derailleur is set, put the catcher in place and tighten it down.