Shimano GRX FC-RX820-1 Crankset - 170mm, 12-Speed, 40t, 110 BCD, Hollowtech II, Black

The Shimano GRX FC-RX820-1 Crankset is a purpose-built gravel drivetrain component engineered to deliver reliable power transfer, improved stability, and long-term durability across varied terrain. Designed specifically for 12-speed GRX drivetrains, this crankset features a single 40-tooth chainring that provides a balanced gear ratio for mixed gravel surfaces, climbs, and fast road sections. Its 110 BCD bolt circle and direct bolt-on chainring design simplify installation and tuning, making setup and maintenance straightforward.

The crankarms use Shimano’s Hollowtech II hollow-forged construction, which combines low weight with high rigidity. Hollowtech II technology places strength where it’s most needed by forging the crankarm body around a hollow core, helping optimize stiffness-to-weight performance and supporting efficient power transfer from rider to drivetrain. The 170 mm arm length offers a responsive pedaling profile suited to a broad range of rider sizes and pedaling styles.

Shimano integrated the GRX crankset’s geometry to work harmoniously with gravel frames and framesets, helping maintain a stable chainline and reducing pedal strikes on rough trails. Its black finish offers a clean, durable surface that resists corrosion and complements a wide range of bike color schemes. The crankset is compatible with GRX-specific bottom brackets and supports chainrings designed for 12-speed micro-spline cassettes, providing smooth shifting and reliable engagement even under load.

Key Features

• Designed for 12-speed GRX gravel drivetrains
• Single 40-tooth chainring optimized for mixed terrain performance
• 110 BCD bolt circle and direct-mount chainring interface
• Hollowtech II hollow-forged crankarms for optimized stiffness and weight
• 170 mm crankarm length for balanced pedaling dynamics
• Gravel-specific geometry with stable chainline
• Durable black finish suitable for varied bike styles
• Compatible with GRX bottom brackets and 12-speed drivetrains

Technical Specifications

• Model: FC-RX820-1
• Speed: 12-speed
• Chainring: 40T
• Bolt Circle Diameter (BCD): 110 mm
• Crankarm Material: Hollow Forged Aluminum (Hollowtech II)
• Crankarm Length: 170 mm
• Chain Compatibility: Shimano 12-speed
• Color: Black