Repair Tech Tuesday: How to Adjust Your Derailleur’s B Screw By Video Share April 7, 2015 Tech Tuesday! B screw adjustment. Posted by Park Tool on Tuesday, December 9, 2014 How to adjust your derailleur’s B screw. Share This: Tweet Video Share These are videos that the Singletracks Staff has collected from around the internet and have deemed worthy to share with you. Subscribe! Enter your email address to receive our top stories via email each week.