XDR is slightly longer than XD to accommodate preexisting road wheels with longer HG spline driver bodies created for 11-speed road cassettes. This was to make it easier for our 85+ hub partners to convert their existing tooled driver bodies to XDR and also to make it easier to provide opportunities to convert old wheels to XDR at a minimal cost to the rider without changing the overall length of the axle, or dish requirement of the wheel.
Why did SRAM create the XDR driver body interface?
Related articles
- What is the difference between XD and XDR driver bodies?
- Will my hub work with your XD driver for the XG 10-42 0r 10-50 cassettes?
- Do XD or XDR equipped wheels require special frame rear dropout designs?
- What is XD, and why is it a thing?
- Do SRAM XD cassettes require different installation tools than traditional cassettes?