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Shimano GRX RX820 2 x 12 groupset

Name: Shimano GRX RX820 2 x 12 groupset
Brand: Shimano
SKU: EVOGRX122XRX820BUNDLE
Price: 799 GBP
Availability: InStock

Shimano GRX RX820 | 2x12 Mechanical Gravel Bundle

The RX820 series represents the pinnacle of Shimano’s mechanical gravel engineering. The Shadow RD+ clutch in the rear derailleur eliminates chain slap on rough terrain, while the 2x12 configuration ensures you always have the perfect cadence for group rides. This bundle offers customisation across the drivetrain, allowing you to choose between the race-orientated 11-34T (Ultegra R8100) cassette or the endurance-focussed 11-36T (105 HG710) for maximum climbing assistance.

The Shimano GRX RX820 2x12 groupset is the ultimate mechanical drivetrain for gravel riders who demand the tight gear steps of a road bike with the ruggedness of a mountain bike. By pairing a 48/31T chainset with a 12-speed cassette, this system provides a massive 507% range—ideal for everything from fast road sections to steep, loose technical climbs.

Build Advice: The "High-Adventure" Setup

To optimise the RX820 groupset for long-distance bike packing or aggressive gravel, consider these specific selections:

The Chain Choice: Go for the CN-M8100 (XT) chain. The Chrome-plated rollers and Sil-Tec surface treatment on the inner and outer plates significantly increase longevity in the dusty or gritty conditions common in gravel riding.
The Rotor Pick: The RT-CL800 (Ultegra tier) is the sweet spot. It features the Ice-Tech FREEZA fins for superior cooling but is more cost-effective than the CL900, which only adds a layer of black heat-dissipation paint to the fins.
The Cassette Logic: If you frequently ride in the Peak District or Lake District, the 11-36T (HG710) is mandatory. The extra 2 teeth on the largest sprocket make a noticeable difference when the bike is loaded with luggage.
Bottom Bracket: For most modern carbon frames, the SM-BB72 is the standard. If you have a threaded steel or titanium frame, the SM-BBR60 is extremely reliable and features better sealing than the basic road versions.

CHOOSE OPTIONS

Left Rear Brake/Shifter

Shimano GRX 12-Speed Lever incl. Brake caliper and Hose - Left Hand 2-Speed (Lever with caliper and hose)

£0.00

Right Front Brake/Shifter

Shimano GRX 12-Speed Lever incl. Brake caliper and Hose - Right Hand (Lever with caliper and hose)

£0.00

Rear Derailleur

Shimano GRX 12-speed rear derailleur - One size - Max 36T

£0.00

Front Derailleur

Shimano FD-RX820 GRX front mech, 12-speed double

£0.00

Chainsets & Cranks

£0.00

Cassettes

£0.00

Chains

£0.00

Select Front Rotor if required

£0.00

Select Rear Rotor if required

£0.00

was £1,239.95

Available to order

£799.00

ADD TO ORDER

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Months	12
Purchase Cost	£799.00
APR	11.90%
Deposit %	10.01%
Deposit amount	£80.00
Loan amount	£719.00
Pay per month	£63.64
Total payable	£843.68

THE DETAIL

Gravel-Specific Ergonomics: The ST-RX820 hoods feature a raised head and textured, anti-slip surface for security in the wet. The brake lever pivot is also higher, providing more leverage when braking from the hoods.
Wider Tyre Clearance: The FD-RX820 front derailleur is designed with a +2.5mm chainline, providing essential clearance for modern, high-volume gravel tyres (up to 53mm or more depending on frame).
Integrated Dropper Control: For technical descents, the optional ST-RX820-LA left lever replaces the front shifter mechanism with a dedicated dropper post actuator, keeping the cockpit clean and professional.
Advanced Rotor Technology: The RT-CL series rotors (CL700/800/900) feature a more robust carrier design that reduces heat-deformation "pinging," ensuring silent braking even after long descents.

SPECIFICATIONS

Component	Option / Specification	Notes
Chainset	FC-RX820-2 (48/31T)	Hollowtech II; 170, 172.5, 175mm.
Cassette A	CS-R8101-12 (11-34T)	Ultegra level; tighter cadence steps.
Cassette B	CS-HG710-12 (11-36T)	105 level; adds a "bail-out" gear for hills.
Chain Options	CN-M6100 / M7100 / M8100	MTB 12-speed chains; M8100 (XT) has Sil-Tec.
Rotors	RT-CL700 / CL800 / CL900	CL900 (Dura-Ace) has heat-dissipation paint.
Rear Derailleur	RD-RX820 (SGS)	12-speed specific with Shadow RD clutch.
Dropper Lever	ST-RX820-LA	Replaces left shifter for 1x or specialized setups.
Bottom Bracket	SM-BB72 (PF) / SM-BBR60 (BSA)	BB72 is Press-Fit; BBR60 is Threaded.
Brakes	BR-RX820 Hydraulic	Flat Mount; 10% wider pad clearance.
UK Price (Est.)	�1,100��1,350	Varies by rotor and cassette choice.

Component	Option / Specification
Chainset	FC-RX820-2 (48/31T)
Cassette A	CS-R8101-12 (11-34T)
Cassette B	CS-HG710-12 (11-36T)
Chain Options	CN-M6100 / M7100 / M8100
Rotors	RT-CL700 / CL800 / CL900
Rear Derailleur	RD-RX820 (SGS)
Dropper Lever	ST-RX820-LA
Bottom Bracket	SM-BB72 (PF) / SM-BBR60 (BSA)
Brakes	BR-RX820 Hydraulic
UK Price (Est.)	�1,100��1,350

Component	Notes
Chainset	Hollowtech II; 170, 172.5, 175mm.
Cassette A	Ultegra level; tighter cadence steps.
Cassette B	105 level; adds a "bail-out" gear for hills.
Chain Options	MTB 12-speed chains; M8100 (XT) has Sil-Tec.
Rotors	CL900 (Dura-Ace) has heat-dissipation paint.
Rear Derailleur	12-speed specific with Shadow RD clutch.
Dropper Lever	Replaces left shifter for 1x or specialized setups.
Bottom Bracket	BB72 is Press-Fit; BBR60 is Threaded.
Brakes	Flat Mount; 10% wider pad clearance.
UK Price (Est.)	Varies by rotor and cassette choice.