microSHIFT ADVENT Super Short Rear Derailleur - 9 Speed Super Short Cage BLK With ClutchmicroSHIFT ADVENT Super Short Rear Derailleur 9 Speed Super Short Cage Black With Clutch. The Super Short version of our acclaimed microSHIFT ADVENT derailleur has all the same features as its larger counterpart but with a small enough cage to fit on a 20" wheeled bike. The ratchet and pawl clutch and return spring tension have been finely tuned to offset the smaller cage and lighter chain allowing the derailleur to deliver fast accurate shifts with a