There are a few common problems with front derailleurs:nn1) The chain can fall off the front derailleur when shifting gears. This is usually due to incorrect adjustment of the derailleur.nn2) The chain can get stuck between the teeth of the front derailleur and the chainring, causing the bike to stop abruptly. This is also usually due to incorrect adjustment of the derailleur.nn3) The front derailleur can rub against the chain or chainrings, causing noise and wear. This is usually due to incorrect adjustment of the derailleur or the chainline.