G4-X SRAM Red XPLR 1x13 + Carbon Wheels

Introduced in 2024, the Colnago G4-X is a dedicated gravel race platform that leaves behind the cyclocross-first compromises of its predecessor, the G3-X. While it retains UCI cyclocross homologation, its primary focus is high-speed gravel competition. The monocoque carbon frame adopts modern standards, including a threaded T47 bottom bracket, a SRAM Universal Derailleur Hanger, and fully integrated cable routing. Colnago also increased nominal tire clearance to 45mm, reflecting the demands of modern race courses without sacrificing compatibility for 2x drivetrains. Positioned alongside the more endurance-oriented C68 Gravel, the G4-X is an uncompromising tool built for aggressive riders who prioritize power transfer and aerodynamic efficiency over plush compliance. It is a speed-focused chassis designed to excel on fast, rolling terrain and punchy climbs.

$9,750
Image pending
Build
Size
Stack573mm
Reach390mm
Top tube560mm

Fit and geometry

The G4-X geometry is tuned for an aggressive, forward-biased racing posture. Colnago slightly extended the reach compared to the previous generation, encouraging a low, aerodynamic tuck over the front end. This elongated position pairs with a relatively slack 71.5-degree head tube angle on most sizes and a consistent 430mm chainstay length across the board. The result is a fit that naturally weights the front wheel, which testers found highly advantageous for maintaining traction on loose, steep climbs.

While this forward weight distribution aids climbing and fast, sweeping corners, it requires a more assertive riding style on technical descents, where getting your weight back can feel challenging. A notable practical benefit of the geometry is the complete absence of toe overlap across all frame sizes, simplifying low-speed maneuvering. Cockpit setup varies significantly by build; the top-tier models feature Colnago’s CC.01 Wide integrated carbon bar and stem, which locks in the fit and limits accessory mounting, while lower-tier builds use a traditional two-piece Deda alloy setup that allows for easy adjustment.

Full specs

Frameset

Frame

Colnago G4-X monocoque carbon frame

Fork

Colnago carbon fork for disc brakes, external cable routing, round-section legs

Groupset

Shift levers

SRAM RED eTap AXS HRD shift-brake system

Rear derailleur

SRAM RED XPLR eTap AXS rear derailleur, RD-RED-1E-E1

Cassette

SRAM XPLR 13-speed cassette, 10-46T

Chain

SRAM RED chain, CN-RED-E1

Crankset

SRAM RED 1x13 XPLR AXS crankset, 40T chainring (crank length: sizes 450–480: 170mm; sizes 520–570: 172.5mm)

Bottom bracket

T47 SRAM DUB Road

Front brake

SRAM RED eTap AXS HRD hydraulic disc brake

Rear brake

SRAM RED eTap AXS HRD hydraulic disc brake

Front rotor

SRAM CenterLine XR Rotor, 160mm

Rear rotor

SRAM CenterLine XR Rotor, 160mm

Wheelset

Front wheel

Vision SC 45 Disc carbon wheel (hooked), 45mm depth, 21mm internal width, direct-pull spokes, 12x100

Rear wheel

Vision SC 45 Disc carbon wheel (hooked), 45mm depth, 21mm internal width, direct-pull spokes, 12x142

Front tire

Pirelli Cinturato Gravel 40 TLR

Rear tire

Pirelli Cinturato Gravel 40 TLR

Cockpit

Stem

Colnago CC.01 Wide integrated cockpit stem (size 450–480: 90mm; sizes 520–570: 100mm)

Handlebars

Colnago CC.01 Wide integrated cockpit handlebar (size 450: 400mm; sizes 480–540: 420mm; size 570: 440mm)

Saddle

Selle Italia Novus Boost EVO Superflow FeC (Model X BB FEC also listed)

Seatpost

Colnago carbon seatpost, 0.15 offset, D-shape section

Grips

Colnago Grip Black bar tape

Builds

The G4-X lineup spans five complete builds, ranging from mechanical Shimano GRX 820 to SRAM Red XPLR. Colnago does not offer a frameset-only option, meaning buyers must select a complete package. The entry points feature 1x or 2x Shimano GRX groupsets paired with alloy Fulcrum Rapid Red wheels and standard two-piece alloy cockpits. Moving up the ladder introduces electronic shifting with SRAM Rival, Force, or Red, alongside carbon Vision or Zipp 303S wheelsets.

A consistent critique across the build range is the perceived value of the stock rolling stock and contact points. Even the premium SRAM Red build, priced near the top of the market, ships with mid-tier wheels and a heavy Selle Italia Model X saddle. Because the frame utilizes standard interfaces like a T47 bottom bracket and a UDH, future upgrades are straightforward. However, riders seeking peak race performance should factor in the likelihood of immediately swapping the wheels and saddle to match the high-end capabilities of the carbon chassis.

Reviews

Reviewers universally characterize the G4-X as a highly efficient, rigid machine that behaves much like a dedicated road bike on the dirt. The frame's exceptional power transfer is a recurring theme, with testers noting that the "bottom bracket area is super stiff" (Velo), making the bike feel remarkably responsive during hard accelerations and steep climbs. On smooth, fast gravel, this rigidity translates into effortless speed maintenance.

However, this singular focus on efficiency introduces a clear tradeoff in comfort. The stiff chassis transmits significant feedback on rougher surfaces, with one tester noting that hitting drainage ditches "sent significant shocks through my hands and feet" (BikeRadar). Consequently, riders must rely heavily on tire volume and pressure to manage vibration over long distances.

Handling opinions split depending on the terrain. On sweeping, non-technical corners, the bike is "stable for cornering" and feels "playable and fun to ride" (Signaturecycles). Yet, when the gradient drops into steep, chunky descents, the aggressive posture can feel demanding. It is a platform that rewards skilled bike handlers but is "not a bike that will make you feel like a hero who rides above your skill" (Velo).