Josh

Thanks folks - an update to some of your questions: 1. bike was not a conversion - made as a 1x, all factory components 2. No play on jockeys on either derailleur, jockeys spin freely. Jockey's on second derailleur replaced once. 3. Shifting smooth (apart from instances where chain has come off jockey). Based on feedback it seems sensible that the cage has broken from the pressure created by the chain coming off the jockey, getting stuck in the cage and stressing the metal. From your posts, possible causes are: Incorrect B-Screw setting, Bent hangar, The wheel itself, the chainline being skew.

Thanks for the insights and advice - very helpful! I’ll check on the jockey play and both, and post feedback later. grateful to know I can just replace the cage! On the first break I think we may have looked for one but probably not hard enough!

Hi Folks, See attached pics. The jockey wheel cage on my wife's bike has broken in exactly the same place as her first derailleur a year ago. The bike was bought in 2021 - we would sometimes have issues with the chain slipping off the jockey wheel. Minor issue, easy to reseat. After about a year the first break happened (2022). we replaced the derailleur, and continued to have issues with the chain slipping off the jockey, but far less frequently. Exactly a year later the same break (this past weekend). Any thoughts as to why this might be happening?