Shimano GRX RX820 2 x 12 Groupset

Shimano GRX Kit Overview

Shimano GRX, designed with gravel-specific ergonomics, optimized gearing, and rugged reliability, offers a quiet, stable drivetrain suited for unpaved adventures. This premium series provides outstanding performance and value with ergonomic designs and gravel-centric gearing.

These are fully boxed UK products.

Included Parts: 

Chain: Shimano XT/Ultegra M8100 12-Speed Chain

• Hyperglide+ technology with specially designed plate profiles for seamless operation with Shimano DCE 12-speed chainrings and cassettes, providing 1/3 faster shift time under load than previous Hyperglide systems
• Outer plate design reduces chain suck, and Sil-Tec surface treatment (PTFE plating) enhances smoothness and durability
• Compatible with 12-speed HG+ drivetrains, includes Quick Link for fast tool-free assembly

Cassette: Shimano 105 CS-HG710 12-Speed Road Bike Cassette (11-36T)

• Hyperglide+ sprockets feature computer-designed tooth configurations with contoured shift gates, ensuring crisp and smooth shifting even under load
• Close-ratio gearing improves energy efficiency with finer cadence control
• Large sprockets mounted on a lightweight alloy carrier for reduced weight and increased rigidity
• Nickel-plated finish provides resistance to corrosion; includes pearl-bright steel lockring
• Compatible with Super Narrow 12-speed Hyperglide+ chains

Front Derailleur: Shimano GRX FD-RX820 12-Speed Double Front Mech

• Designed for fast and precise shifting performance with increased tire clearance (2.5 mm chainline adjustment)
• Braze-on mount compatible, with seat tube adapters available (SM-AD91) if needed
• Compatible with 12-speed Hyperglide+ chains and suitable for double chainsets
• Wide-range 17T capacity, compatible with 46-50T outer chainrings

Chainset: Shimano GRX FC-RX820 12-Speed Double Chainset

• Optimized for gravel with smaller gear steps to maintain cadence on mixed terrain
• Wider gear range with gravel-specific ratios, providing a balanced riding rhythm on rough surfaces
• 17T front range with a gear combination of 48-31T

Rear Derailleur: Shimano GRX RD-RX820 12-Speed Double Rear Mech

• SHIMANO SHADOW RD+ design for secure and silent rear shifting on rough terrain
• Adjustable chain stabilizer prevents chain slap and drops
• ON/OFF stabilizer switch to match shifting stability to terrain
• Maximum front difference: 17T; top sprocket: Max 11T, Min 11T; low sprocket: Max 36T, Min 34T
• Total capacity: 42T

Shifter/Brake Set: Shimano GRX ST-RX820 Left (2-Speed) & Right (12-Speed) STI Levers with BR-RX820 Disc Brake

• Gravel-optimized brake lever ergonomics for enhanced comfort and control
• Anti-slip coating on brake lever surface, optimized for use with flared handlebars

Genuine new, boxed Shimano product (not OEM parts) - Biketart are proud official Shimano stockists.