An article of footwear with adjustable stiffness is provided. The article of footwear in the form of a snowboard boot is provided with adjustable tensioning systems that are disposed on either side of an inner liner of the snowboard boot. The adjustable tensioning system includes a comb body structure having flex portions made of a plurality of extending fingers with a flexibility that can be controlled by the adjustable tensioning system. Depending on the level of tension applied by the tensioning system, or lack thereof, a range of flex profiles having varying amounts of stiffness are available to the wearer to adjust the overall stiffness of the snowboard boot.