The SRAM X9 hub is yet another example of an excellent offering on the part of SRAM's superb R&D and engineering department. The flanges are machined out as much as possible to reduce weight and terrain strength and stifness. The cartridge bearings are extremely high quality and are not only durable, but spin effortlessly. Alloy hub shell and oversize axle are again light and durable.
20mm is the standard for all-mountain and gravity runs. The super oversize(over twice the diameter of standard hubs) produces the utmost in stiffness, which in turns promotes better handling manners and tracking of the front wheel. The improvement is noticeably better. Plenty of fork options on the market make this design relevant and necessary for the type of riding it was designed for. Not only is it a good choice for all mountain thrashing, but for 29ers as well from the added flex due to the leverage of a larger diameter wheel.