The return-spring tension is boosted to force crisp downshifts under load and there are almost 40 variations of the XX front changer available with band-clamps, direct-mount frame interfaces and in high- and low-pull cable configurations.Īdvantages for using SRAM’s 2×10 system are a better chain line (49.5 millimeters), and a slightly narrower Q-factor (the distance between pedal centers)?but the best news is that the XX crankset shifts almost instantly. The cage is steel and its parallelogram arms are forged aluminum. The XX front derailleur looks beefy and it is. Shifting from the smallest to largest cogs in while in the largest chainring is possible without any noise, while the granny can be cross-chained within one or two cogs without rubbing on the cage, depending upon your bike’s frame geometry. SRAM wanted the front derailleur to shift across the entire gearing range without rubbing on the chain?and they nearly succeeded. The entire rear derailleur uses T-25 Torx screw-heads, which are the same size used for disc brake rotor screws, and both pulleys use ceramic bearings to cut friction to near zero. The main pivot bolt is aluminum, and the spring and hardware are titanium. SRAM makes the outer parallelogram from forged aluminum, while the inner is forged magnesium. While the rear derailleur shares much of the X.0’s geometry and mechanical specifics, the carbon/aluminum cage uses a slightly offset upper pulley pivot to allow it to cover the wider spread of the 11-36 cassette.
We think you will agree after a walk-through of XX, that they made the correct decision. Don’t start fretting about compatibility, however, because chain-line and cross-over design issues related to 2×10 forced SRAM to begin the project from scratch. This means that the new ten-speed shifters and derailleurs are not compatible with X.0 nine-speed parts. So are the trigger shifters, which use SRAM’s “Exact Actuation” cable metering system that is standard fare on its Force, Red and Rival road groups. The front and rear derailleurs are ground-up designs that are configured specifically for XX.
SRAM’s XX, however, will be tough to beat. It’s a winner and we will be hearing an immediate response from competing parts makers. The 36-tooth big cog looks comical at first, but it is in use constantly and remains the key ingredient of the XX ensemble. We think that many trailbike riders will embrace it as well as racers (who are already riding cobbed up 2×9 drivetrains). Well, SRAM hit it right by containing XX within a useful framework?and that framework is cross-country.
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