Comment by asdff

It's not like derailleurs are plagued with issues or costly maintenance as it is. It takes a lot of riding to knock them far enough out of spec where its a problem, and a tuneup at a bike shop is like $25. Pay that once a year and you will have like zero problems with your bike unless you crash it badly. If its a matter of protecting the derailleur from damage like on mountain bikes, you can install a guard for a few bucks.