Shimano's Deore XT Dyna-Sys 10-Speed Crankset boasts race-worthy efficiency. Shimano incorporates the crankarms and the bottom bracket spindle into a single unit so you shave grams without losing a drop of valuable pedal power. The 42/32/24 ratio gives you smaller jumps between gears, making for more efficient shifting and pedaling, especially with full-suspension bikes. This design also sports external bottom bracket bearings that increase rigidity and durability. And, the carbon/steel composite middle ring adds rigidity for better shifting, increased service life, and smooth, flex-free power delivery.