The Wolf Tooth RoadLink derailleur hanger extension offsets the position of your R8000 and R9100 road derailleur making it possible to run a wider mountain bike cassette ideal if you’re looking to convert to a 1x set up with minimal fuss.   If you're looking for the simplicity of a single chainring up front or even just want lower bail-out gears on your double without changing your existing groupset or losing shifting performance and chainwrap, then the RoadLink is for you.     Features Fits Shimano R9100-generation Dura-Ace, R8000-generation Ultegra, and R7000 105 rear derailleurs. Fits standard derailleur hangers only. Direct mount derailleur hangers are not supported. These are not common and the stock b-link that the RoadLink DM replaces will not be present on bikes with a direct mount derailleur hanger. Optimized for use with 11-36t, 11-40t, and 11-42t 11-speed cassettes. Will improve performance with 10-42t 11-speed cassettes, but not to factory levels. Does not change the derailleurs total chain wrap capacity. .