The 2006 sram x0 product line is setting a new benchmark mountain bike shifting at the formula 1 level never before has a shifter and rear derailleur been faster lighter and more precise than the new sram x0 systemthe new x0 rear derailleur has a carbon cage and new design the x0 triggers have been added to the line and with their patented zero loss travelt youll enjoy the fastest fully adjustable shifting ever the x0 twister remains a part of the family giving more options to choose shift