Shimano\'s new and improved Dura-Ace 9000 Series Mechanical Groupset now features 11 speeds to help with even more types of road conditions. Another major benefit is the crankset is dual compatible. What does this mean? This means that you can buy a 53/39 crank one day and then use the 50/34 chainrings the next without needing to change the entire crankset. Overall the new Dura-Ace 9000 Road Groupset is more versatile and more reliable then ever.