The Shimano FC-RX820-1 crank balances weight savings, optimized efficiency and an array of gearing options that cater to the segmented demands of mixed-terrain riding. By pairing a 10-45T or 10-51T cassette with 40T and 42T chainrings, riders can choose closer gear steps or ultimate range. The FC-RX820-1 comes in 170, 172.5, and 175 mm crank arm lengths, providing an additional level of customization.
Shimano GRX, with its gravel specific ergonomics, optimized gearing options, rugged reliability, and quiet and stable drivetrain, sets itself apart from the rest of the component world.
Technology
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.
Features
- The HollowTech II 12-speed single chainset offers optimum gearing for mixed terrains and riding styles
- Designed to work with HollowTech II type bottom bracket cups
- Compatible with 12-speed Hyperglide+ chains
- Anodised aluminium crank arms
- Lightweight aluminium chainring
- 4 arm, 110mm bolt circle diameter
Specifications
- Speed: 12
- Chain Compatiblity: Shimano HG 12-Speed
- Chainline: 49.7mm
- Q-Factor: 151mm
- Weight: 644g (40T), 656g (42T)













