Shimano GRX FC-RX820 1x12 speed Crank 40T 42T

Shimano GRX FC-RX820 1x12-speed Crank 40T 42T
The new GRX FC-RX820-1 HOLLOWTECH II 1 x 12-speed crankset offers the perfect synthesis of light weight and high efficiency for mixed terrain riding. The transmission options address the specific requirements of Gravel and provide tighter graduations for a smooth rhythm.
For your riding freedom: the Gravel GRX 1x12-speed FC-RX820-1 Crank 40T from Shimano
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 chainring, riders can choose closer gear steps or ultimate range. The FC-RX820-1 comes in 170, 172.5, and 175mm crank arm lengths, adding an additional level of customization.
Gravel cycling is not meant to be overly complicated. The heart and soul of cycling’s drop bar, dirt road discipline is rooted in simplicity, inclusivity, and adventure. No ride is out of bounds. All are welcome to join. Gear should be functional and reliable but need not break the bank. That’s why whether you’re a grizzled gravel cycling veteran or brand new to the road (or trail) less traveled, you’ll appreciate the latest iteration of Shimano’s groundbreaking—and industry-first-gravel-specific GRX component group. Designed to help you get the most from your next unpaved adventure, RX820 delivers top-tier performance without an over-the-top price.

If your next outing includes pushing for personal PRs or duking it out at the sharp end of a race, you’ll appreciate the gear steps of the RX820 1x12 setup with a 10-45 cassette paired with a 40- or 42-tooth chainring. Just like its 11-speed predecessor, RX820 delivers smooth, reliable shifting but now features a wider gear range and extra cog, making it easier to find the optimal cadence for maintaining your position in the pack.

If your next outing includes pushing for personal PRs or duking it out at the sharp end of a race, you’ll appreciate the gear steps of the RX820 1x12 setup with a 10-45 cassette paired with a 40- or 42-tooth chainring. Just like its 11-speed predecessor, RX820 delivers smooth, reliable shifting but now features a wider gear range and extra cog, making it easier to find the optimal cadence for maintaining your position in the pack.

If all-day—or multi-day—adventures heavy on climbing are your thing, the new RX820 1x12 UNSTOPPABLE option with SHIMANO’s wide-range, 10-51T cassette offering is ideal. Paired with a 40T or 42T chainring, you'll never run out of gears, even on the steepest jeep road or high mountain ascent. And like the 10-45T, 1x12 option, this group features an integrated SHADOW PLUS chain stabilizer for optimal chain security and an ON/OFF switch, making wheel removal quick and easy if you happen to puncture.

Both 1x12 options utilize Micro Spline, Shimano’s lightweight aluminum freehub design that seamlessly integrates with 10-tooth top gears and features smaller, more widely spaced splines that limit cog damage. The 1x12 gravel-specific crankset is offered in three crankarm lengths, giving you the option to choose the ideal Shimano GRX setup for your needs and riding style.

Features - Shimano GRX FC-RX820-1-12 | 1x12-speed Crank | 40
Gravel gear ratios preserve riding rhythm over rough surfaces with wider tires
Optimum gearing for mixed terrains and riding styles
10-45T and 10-51T cassette options serve array of riding styles
Product features
Use: Gravel, Cyclocross
Group: GRX
Model: FC-RX820-1
Gradation: 40T
Q-Factor: 151mm
Threaded BB shell width: 68 / 70mm
Gear front: 1-speed 
Gear rear: 12-speed
Construction: Hollowtech II
Compatible Chain: 12-speed HG
PCD: 110mm
Chain line: 49.7mm
Recommended BB Pressfit: SM-BB72
Recommended BB BSA: SM-BBR60
Crank arm length (choose variant)
170mm
172.5mm
175mm
Material
Crank arm: Aluminum Anodized
Crank axle: Steel Plated
Chainring: Aluminum Anodized
Color
Series color
Weight
approx. 655g/172.5mm (manufacturer information)
Scope of delivery
1 x Shimano GRX 1x12-speed Crankset FC-RX820 40T
Bottom Bracket BSM-BBR60 BSA / Pressfit SM-BB72 not included!
Technologies
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.