The GoatLink 11 hanger extension offsets the position of your 11-speed Shimano mountain bike rear derailleur allowing you to be able to run a wider range cassette while improving performance. Same ergonomics and reliability of Shimano shifters and derailleurs Gear range, simplicity and quietness of SRAM 1x11 drivetrain High-performance and lightweight This project began with the desire to run 11-speed Shimano derailleurs and shifters with SRAM 10-42t XD cassettes. Granted the combination can work without modification - but performance wasn't quite what we'd expect from Shimano and SRAM's finest. When used with a 10-42t cassette, the GoatLink 11 re-positions SLX M7000, XT M8000 and XTR M9000 rear derailleurs such that free chain length between the cassette and the top derailleur pulley is within 1% of what Shimano intended while cassette tooth engagement in the smallest cog is improved by 27%. Knowing that certain situations call for a range beyond that provided 10-42t or 11-42t cassettes, we tweaked the GoatLink 11 to also significantly improve Shimano 11spd rear derailleur performance with extended-range like the Wolf Tooth GCX 44t modified 10-44t XX1 or X01 cassette. Compatibility Cassette - Compatibility 11-40 - Not Required 11-42 - Not Required 11-45 - GS/SGS Derailleur 11-46 - GS/SGS Derailleur 10-42 - GS/SGS Derailleur 10-44 - GS/SGS Derailleur (Wolf Tooth GCX44) 10-45 - Not Optimized 9-44 - Not Optimized Other notes: The GoatLink 11 is compatible with SLX M7000, XT M8000 and XTR M9000 series 11-speed Shimano rear derailleurs. Not compatible with Shimano RD-RX812 or RD-RX817 due to the 31T capacity limitation. The GoatLink 11 mounts only to standard derailleur hangers. Double chainrings (2x) is supported and requires a long cage (SGS) rear derailleur with no more than a 12t difference in front chainrings (with an 11-46t cassette). Triple chainrings are not supported. Direct Mount native frames and SRAM derailleurs are not supported.