Shimano Ultegra FC-R8100 12-Speed Double Chainset

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Brand	Shimano
Colour	Grey

Shimano is a Japanese multinational corporation synonymous with cycling. Constituting 50% of sales in the global cycling market, and with their parts spanning across all types of bicycle, it is a highly reputable business that is constantly developing and innovating its assets.

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Shimano Ultegra FC-R8100 12-Speed Double Chainset

The HollowTech II 12-speed Ultegra chainset offers an ideal balance of light weight and stiffness, making it the perfect choice for both enthusiast and competitive riders.

Ultegra's new FC-R8100 crank maintains the same quick, precise front shifting and efficient power transfer that Shimano riders have grown accustomed to, but with even more crank arm length options. Spanning 160 to 175mm in length, Ultegra cranks now cater to smaller riders, triathletes, and cyclists curious about shorter crank arms.

An integral part of Shimano's new 12-speed road lineup, the FC-R8100 crank builds upon Shimano's legendary front shifting and transmission efficiency. With new refinements for seamless 12-speed shifting, the Ultegra crank is now offered in lengths from 160 to 175mm, bringing performance and improved fit for smaller riders, triathletes, and riders with specific biomechanical requirements.

Technology

HollowGlide

Hollow technology on outer chainring. High rigidity hollow structure cuts down on weight yet maintains strength. Better power transfer and quicker and more precise front shifting.

HollowTech Crank Arm

Hollow forged crank arms; a light weight crankset not only reduces the bike’s weight, but decreases rotating mass to aid in acceleration. The challenge is to reduce the weight of the crank without reducing its strength and rigidity.

Shimano’s advanced forging technology has solved the problem through the HollowTech crank. Just like high quality frame tubing, a hollow crank arm can provide amazing strength and rigidity at very lightweight.

HollowTech II

Providing the best balance of stiffness, strength, weight and rotating performance. The concept of HollowTech II technology is focused on producing a superior crankset which will maximize a rider’s power transfer. The rigidity of the crankset ensures pedaling efficiency while its weight, a key element of the crankset, you want light, aids in cycling longer distances over which the rider needs to pedal more. Naturally, Shimano strove for the optimum balance between the conflicting needs of stiffness while producing a lightweight crank. HollowTech technology is an ultra-lightweight hollow crankarm created by Shimano with the company’s own proprietary forging technology that also maintains rigidity. The addition of HollowTech II technology integrates the bottom bracket axle with the right crankarm for more stiffness and a weight savings to achieve a high-dimensional balance. Its outboard bottom bracket bearing system provides better weight distribution and more pedaling stability, allowing for more efficient power transfer.

The HollowTech II crankset has been developed by pursuing the optimum balance of stiffness & rotating performance in a lightweight and beautiful crankset design. Moreover, HollowTech II crankset has a high-precision sealing in the bearing area to increase durability maintaining the excellent rotating performance for long periods.

24mm Diameter Axle And Bearings

Why choose the 24mm axle and bearings for the HollowTech II crankset?

The diameter of the Bottom Bracket axle and bearings was of primary importance for the development because the Bottom Bracket axle area is tied to such key elements as stiffness, strength, weight and rotating performance.

What’s important is the total balance of crankset

In addition, taking the crankset as a whole, the total balance of crankarm rigidity, axle stiffness, bearing position and others is essential. Indeed, the crankset is designed by careful consideration of the total balance of those elements to prevent breakage.

Outboard Bearing

For most frames with 68mm Bottom Bracket shells, HollowTech II with 24mm axle can set the bearing position outside of the frame to provide better weight distribution and more stability.

24mm Diameter Axle And Bearings Provide Optimum Balance For The Crankset

After studying all these problems thoroughly, we made the decision to adopt the 24mm diameter axle and bearings, which have the optimum balance, for the HollowTech II crankset.

In addition, an examination of the total crankset, including the crankarm and gears, proves the optimum balance of rigidity, weight and rotating performance for the ultimate transfer of power to your bike. HollowTech II is simply the most optimized crankset design on the market.

Features

HollowGlide hollow outer chainring gives vast improvements in rigidity by virtually removing outer chainring flex and hugely improves shift performance, even under high load
The chainring teeth have been developed to work in conjunction with 12-speed HG chains for increased contact to provide greater efficiency and improved power transfer
Industry leading HollowTech II cold forged 4 arm hollow cranks have been evolved for maximum rigidity while reducing weight
Wide gear pitch spacing increases clearance between chain and leading teeth to provide compatibility to frames with O.L.D. 135 / 142
A wide range of chainring options and crank arm lengths are available to meet the needs of all riders and racing disciplines
HollowTech II integrated bottom bracket uses a wider bearing placement and larger axle diameter for increased stiffness and efficiency
HollowTech II integrated bottom bracket seal design has minimal bearing interface ensuring smooth rolling and increased durability (sold separately)