Shimano 105 FC 5800 11 Speed Crankset 5236t. The 4 arm awesomeness that's revolutionized Shimano's Dura Ace and Ultegra cranksets has now trickled down to the 105 level with the FC 5800 11 speed crankset. While shedding grams and increasing stiffness over the previous, 5 arm 105 cranks, the 4 arm design features the same bolt pattern for compact and standard sized road chainrings so the versatility of the crankset is maximized. No need for a new crankset if you seek to change gearing simply swap out the chainrings. That's a win win situation in our book.