It is done I copied travis brown when he used Sram Red with Sram XX on his mountain bike. Instead we (John Mc. from Fort Worth cycling, Josh from Ft Worth Cycling Fitness in Fort Worth) put Sram XX with a Sram XX cassette on my TREK TTX time trial bike, which has SRAM RED Integrated Shifters. Look at the pics. SWEETNESS, SO SWEET it is BITTER SWEET.