Santa Cruz Heckler 9 CC 29 RSV Sram X01 Eagle AXS 12s Reserve 31|DH/Reserve 30|HD: Heckler's latest generation has a larger interchangeable battery, allowing riders to expand their map , accessing previously unreachable and less used routes. Heckler has mixed or dual 29-inch wheel size options. Wheel size isn't the only option for riders.