Colnago G4-X Shimano GRX 820 2x

Name: Colnago G4-X Shimano GRX 820 2x
Brand: Colnago

2025 RoadRace Manufacturer page

Suspension: Rigid
Wheels: 700c
Drivetrain: 2 × 12 31–48t / 11–36t
Gear range: 507%
Brakes: Hydraulic disc

Sizes

Size guide

45cm
48cm
52cm
54cm
57cm

The manufacturer did not publish rider heights for these sizes.

Components

13 of 17 identified

Parts found in a manufacturer catalog show their brand, model and key numbers, and the steps show how precisely they are identified: brand, series, model, or the exact product. The info button has every detail and the text the manufacturer published.

Drivetrain

7 parts

Bottom bracket
- Acros
Cassette
- Shimano
Chain
- Shimano Deore XT CN-M8100
CN-M8100
Crankset
- Shimano GRX 31t
Front derailleur
- Shimano GRX FD-RX820 2 speeds
FD-RX820
Rear derailleur
- Shimano GRX RD-RX820 12 speeds
RD-RX820
Shifters
- Shimano GRX

Brakes

2 parts

Brake levers
- Shimano GRX ST-RX820
ST-RX820
Brakes
- Shimano
RX-820RT-MT800

Wheels and tires

4 parts

Front hub

Aluminium, Sealed Cartridge Bearings, Aluminium, Sealed Cartridge Bearings Not identified
Rear hub

Aluminium, Sealed Cartridge Bearings, Aluminium, Sealed Cartridge Bearings Not identified
Rims

Front: 24 mm; Rear: 24 mm, Front: 24 mm; Rear: 24 mm Not identified
Tires
- Pirelli

Cockpit and contact points

4 parts

Handlebar
- Deda
Saddle
- Selle Italia
Seatpost

Carbon seatpost, 0.15 offset, "D-Shape" section, Carbon seatpost, 0.15 offset, "D-Shape" section Not identified
Stem
- Deda

Sizes and geometry

5 sizes Open in the geometry plotter

Complete rider-height ranges are not published for these sizes. You can still explore the geometry below.

Size 52cm

Table

Geometry diagram unavailable

The drawing needs wheelbase, head tube length and seat tube length, which the manufacturer did not publish. Available facts remain in the table.

Size Reach Stack

Complete manufacturer geometry table 5 published sizes

Complete manufacturer geometry by size
Measurement
Frame
Reachmm	371	380	390	400	410
Stackmm	535	554	573	591	600
Top tube lengthmm	524	539	560	581	596
Head tube angle	71°	71.5°	71.5°	71.5°	71.5°
Seat tube angle	74°	74°	73.5°	73°	73°
Chainstay lengthmm	430	430	430	430	430
Bottom bracket dropmm	72	72	70	70	70
Bottom bracket heightmm	264	264	266	266	266
Stack/reach ratio	1.44	1.46	1.47	1.48	1.46
Suspension and parts
Crank lengthmm	170	—	—	—	—
Handlebar widthmm	400	400	420	420	420
Stem lengthmm	90	90	100	110	110

Not published by the manufacturer: Seat tube length, Head tube length, Wheelbase, Front center, Standover height, Fork rake, Trail, Front travel, Rear travel, Stem angle, Seatpost length and Dropper post travel.

Specifications

Frame and fork

Intended fit: Unisex
Fork material: Carbon

Suspension

Suspension configuration: Rigid

Drivetrain

Derived by Bikelake

Front chainrings: 2
Smallest chainring: 31
Largest chainring: 48
Rear sprockets: 12
Smallest sprocket: 11
Largest sprocket: 36
Lowest gear: 25.0 in
Highest gear: 126.6 in

Wheels and brakes

Wheel configuration: Same size
Brake type: Hydraulic disc

Fit and controls

Seatpost: Rigid seatpost
Shifting: Mechanical

Additional specifications

Bottom bracket standard: T47
Wheel material: Aluminum
Wheel size: 700c

Technical analysis

3 measures

How these figures sit among bicycles of the same class and model year. Context, not a ranking.

Lowest gear

25.0 gear inches

This value is below the central range for this class.

Cohort: Road / Race Model year: 2025
Sample: 762 bicycles with this information
Coverage: 78.1% of the class

Highest gear

126.6 gear inches

This value is below the central range for this class.

Cohort: Road / Race Model year: 2025
Sample: 762 bicycles with this information
Coverage: 78.1% of the class

Shifting

Mechanical

643 of 969 bicycles with this information use electronic shifting.

Cohort: Road / Race Model year: 2025
Sample: 969 bicycles with this information
Coverage: 99.3% of the class

Gearing

Estimated speeds at 80 rpm

Lowest gear: 9.6 km/h
Highest gear: 48.5 km/h

Total gear range 507%

Technical details and class reference

These speeds describe the gearing at the selected cadence, not how fast you can ride.
Calculated from published gear-inch values and their wheel-size assumptions.
These gearing values describe the bicycle, not a selected frame size.
A 100% range means one ratio; 500% means the highest ratio is five times the lowest.
For e-bikes, motor assistance cutoff is not represented.

Gear-inch range

Lower gear-inch values travel less distance per pedal revolution; higher values travel farther.

This bicycle: 25.0–126.6 gear inches
Class reference (p10–p90): 28.2–139.2 gear inches; The band runs from p10 for the lowest gear to p90 for the highest gear.

Cohort: Road / Race Model year: 2025
Lowest gear: 762 bicycles with this information, 78.1% of the class
Highest gear: 762 bicycles with this information, 78.1% of the class

Lineup changes

The published facts that differ across this family's builds and from the same model a year earlier. Missing information never counts as zero.

Differences across 2025 builds

Differences across 2025 builds
Specification	This bicycle Colnago G4-X Shimano GRX 820 2x	Colnago G4-X Shimano GRX 822 1x	Colnago G4-X 825 2x Shimano GRX Di2	Colnago G4-X SRAM Force AXS	Colnago G4-X SRAM Force XPLR AXS 1x	Colnago G4-X SRAM Red AXS
Drivetrain
Front chainrings	2	1	2	1	1	1
Smallest chainring	31	42	31	40	40	40
Largest chainring	48	42	48	40	40	40
Rear sprockets	12	12	12	12	13	12
Smallest sprocket	11	10	11	10	10	10
Largest sprocket	36	51	36	44	46	44
Lowest gear	25.0 in	23.9 in	25.0 in	26.4 in	25.2 in	26.4 in
Highest gear	126.6 in	121.8 in	126.6 in	116.0 in	116.0 in	116.0 in
Cockpit
Shifting	Mechanical	Mechanical	Electronic	Electronic	Electronic	Electronic