SRAM GX1 comparability with double crankset I am considering purchasing a bike with SRAM's GX1 11x1 gearing but I would like to switch it to use a double crankset.  

Is the SRAM GX1 rear derailleur and cassette compatible with a dual crankset?  

The bike says: 


  This frame is compatible with both 1x and 2x drivetrain setups.  A removable direct mount front derailleur bracket allows for clean 1x build.  






Edit: The Compatibility Map 2016 MTB Components is here.  Still trying to figure out how to read it...
According to the chart, The GX long cage derailleur is good  for an 11-42 cassette (Yellow triangle) and a 2x11 crank set (Light blue triangle). Also according the chart, all 1x11's should already be long cage derailleurs, but you may want to check the bike before you buy to be sure.