I am an avid cyclist and know what exactly what I am in need of. . . With that being said, I really hated the condescending attitude of the mechanic who tried to convince me that SRAM and shimano were completely interchangeable and there was no difference between the two when it came to drivetrain components. . . .walked out and will never go back. If I were running the store I would ask a few more questions to potential customers before trying to sell them something. . .their team riders have the same attitude at events, should have known better. Go up the road to the Trek store or to Slippery Pig in Phoenix.