Shimano Ultegra FC-R8000 Crankset
Shimano's Ultegra FC-R8000 Crankset doesn't just borrow from R9100 Dura-Ace, it is a true standard to be upheld, with the same technology and design with only marginal changes in finish. The new graphic design element of the R8000 Crankset is bold and assertive, which is how most of us like to believe we approach every ride, even when we really just go for a quiet spin. Enjoy the new frame use flexibility, improved wide range shifting and overall performance of the refined design whether you are using mechanical or Di2 electronic shifting.
It is safe to say that no other company or lab has built the body of research that Shimano has into every aspect of crankset and chainring design. Certainly no has held as many patents in this area. Shimano added width and size to the drive side arm for optimal power and efficiency in the most crucial phase of the pedal stroke. Carrying the structure closer to the chainring mount junction just above the oversized arm, more direct power and overall stiffness is applied to the highest stress point on the crank and ring in the drive power phase. Keep in the mind that the asymmetric spider has the same proprietary BCD as the other 11-speed series cranksets.
As mentioned, the spider and arm design of the FC-R8000 is not the only advancement. Continuing with complete commitment to system integration, the teeth of the chainrings have been re-engineered for greater efficiency, reduced friction and wear, and faster, quieter shifting performance (with mechanical or Di2 systems). The reconsideration of the tooth profiles was also driven by the more extreme chainlines found on today's shorter chainstay frames, which when combined with greater cassette range and new rear spacing, totally changes the load the chain must manage for safety, as well as shifting performance. To create a little more diagonal clearance the inner chainring has been offset .4mm inboard to the center of the bike. This development necessitated changes to frame clearance of the FD-R8000 Front Derailleur, which brings up an upgrade/compatibility issue. The FC-R8000 Crankset should only be run with the FD-R9100 or R8000 Front Derailleur for optimal shifting. While backwards compatible with 9000 and 6800 series, the shifting is so-called B-Level" . We recommend replacing the front derailleur and crankset together, and for optimal performance, also the Dual Control shift levers, which have been designed heavily around the new front and rear derailleur requirements.
In all other respects, the technical aspects are the same as the previous 6800 model. This is the 24mm spindle Hollowtech II system, with the plated steel axle part of the driveside spider. As with the previous designs Shimano does not provide a bottom bracket with the crankset due to the sheer variety of frameset standards. Shimano offers the threaded external cups of the BB-R60, and the PressFit SM-BB92-41B for 41mm diameter shells. The stiff, Hollowglide chainrings are still light, and fastened with anodized aluminum bolts. The inner ring is lightweight anodized aluminum, while the large ring assembly is a bonding of anodized aluminum and CFRP composite. The non-drive arm slide onto the crank axle and the splines and notches align for a precise fit, while the crank fixing bolt sets the bearing adjustment and the offset pinch bolts fasten the arm to the spindle.
Shimano offers the Ultegra FC-R8000 Crankset in the common lengths and chainring combinations, so choose the item that is right for your needs. All of the ring sizes work on the same proprietary asymmetric 4-arm spider, and replacements are available.The only variation you see is in the 46T large ring of the 46-36 combination, where the large ring is all aluminum, no CFRP inner plate. The efficiency, durability and overall performance of the R8000 crankset is only surpassed by it's Dura-Ace progenitor, so spin through your next ride knowing your power transfer and shifting performance are top notch.
- Redesigned 4-arm 11-speed asymmetric road double chainring crankset, with optimal power transfer, positioning and shift refinement
- 24mm Hollowtech II design with driveside integrated steel, plated axle; non-drive arm
- Driveside arm has been made larger, offset towards ring for optimal force in stroke
- Hollowglide chainrings feature new tooth profiles for improved shifting, less wear
- Large ring from anodized aluminum/ CFRP composite
- Small ring is anodized aluminum, and has been offset inboard to frame .4mm
- Shimano recommends only using FD-R9100 & R8000 with R8000 crankset
- Rings fastened underneath with anodized aluminum bolts
- Proprietary 4-arm 110mm asymmetric BCD in all sizes
- Crank arm/chainring finish is anodized Black with fade/li>
- Effective chainline: 43.5mm
- Q-factor: 146mm
- Optimized for HG-EV 11-speed/ HG-X11 Shimano chains
- Does not include bottom bracket
- Crank lengths: 165mm, 170mm, 172.5mm, 175mm
- Chainring combinations: 46-36 (aluminum-only 46T ring), 50-34, 52-36, 53-39
- Weight: 674 grams (170mm, 50-34)