The luminous crankset shown above uses Hollowtech II technology, as featured on this year's XTR.
Here's the tech info as supplied by Shimano.
FC-7800 (Crankset with integrated bottom bracket)
Hollowtech II design
Q-Factor remains same as FC-7701/BB-7700
Minimal bearing interface for smoother rolling
Outboard bearings are 82 mm apart. (BB-7700 bearings are 53.8 mm apart)
Relieved outer chainring, lightweight and very rigid with superior shifting
Weight is anticipated to be 30 grams less than current FC-7701 /BB-7700 combination.
Read what UK consumer bike websites, and their readers, think about the kit here: