Prevent chain suck
When shifting between the front
The cause may be bent teeth on your chainrings or an incorrectly adjusted front derailleur.
However, this is mainly the result of worn chainrings – most often because an edge has formed and when shifting the chain gets stuck causing the chain to get jammed between chainstay and crank.
If the chain is completely wedged in between crank and chainstay, then you’ll need to take off the crank to free it.
Hint: Check chain wear and regularly and replace chain and all other parts of the drivetrain if they are worn out