From world cup racing to Marathon to downhill XX1 is taking the mountain bike world by storm for some big reasons. XX1 is about 200 grams lighter than the next lightest cross country group because there is no front derailleur, shifter or front cabling required. Secondly, the chainring is engineered to retain the chain where chainrings on double and triple systems needs chainrings that allow chain movement. Because there is a reduced need to reel in chain slack, the rear derailleur can be designed for faster shifts and quiet performance with chain slap virtually eliminated.
The carefully thought out XX1 cassette is one of its keys to XX1's success. It has 11-speeds (10-12-14-16-18-21-24-28-32-36-42) with basically a higher high and lower low so you will have all the bases covered with only a need for one chainring in front. Optional chainrings can help fine tune gearing, but everyone we have talked is greatly impressed with the wide range and even, optimized steps. Durability should be excellent as the XX1 cassette is made from a single piece of tool-grade steel and then machined to a light 260 grams with proven X-Dome technology.The new XD driver body design that allows the use of a 10 tooth small cog and provides an improved interface with the cassette. A precisely made sleeve inside the cassette threads directly into the XD driver body (the cassette installed and removed with a standard Shimano/SRAM lockring tool). The sleeve/cassette interface is much better than a standard cassette on a splined hub which can work loose or allow the splines of the body to become gouged. Another benefit of the XD drive system is a reduction in weight of 6-8 grams.Features
Installs on a XD hub driver body made specifically for the XX1 cassette. Most major manufacturers offer hubs with XD free hub bodies or XD free hub body conversions