The 6800 series HollowTech II Ultegra crankset uses a new 4 arm design that is lighter than the previous 5 arm 10 speed version without compromising its structural integrity. In fact, Shimano tells us they are just as strong and rigid as the old 5 arm version, just lighter. They also added additional chain ring configurations, ranging from compact to standard and everything in between. To keep things uncomplicated, the same 110mm bolt circle diameter is compatible with every chain ring option in the Ultegra 6800 lineup.
Shimano does not include the SM-BBR60 bottom bracket with 6800 cranks. Click SM-BBR60 to see the Ultegra 6800 bottom bracket.