Question: is shimano grx compatible with ultegra?
Answer: Shimano GRX 800-level components and 11-speed GRX 600-level components are compatible with current DURA-ACE, ULTEGRA, and 105 road groups. Shimano GRX 400-level and 10-speed GRX 600-level components work great in conjunction with the 10-speed Tiagra road groupset.