GENESIS Croix de Fer 40 – Reynolds 725 / GRX 1x12

Recap

Reynolds 725 steel platform with Shimano GRX 1×12 drivetrain and hydraulic brakes, built around a thru-axle configuration.

The Croix de Fer 40 is oriented toward mixed-surface riding with greater continuity on gravel and a simplified drivetrain setup, while maintaining a structure suited to extended real-world use.

Positioning and use logic

The Croix de Fer 40 sits within the range as the more direct and functional gravel interpretation of the platform. It retains the structural foundation of the series — Reynolds 725 frame, stable geometry, and load-ready design — but introduces a precise build choice: a 1x drivetrain.

This defines the bike’s behaviour more than the simple component difference would suggest. Gear management becomes more immediate, chainline stability improves, and use becomes more continuous when the surface shifts between compact, rough, and variable terrain.

It makes sense for riders alternating between tarmac and gravel, but tending to favour routes where surface consistency is not guaranteed, or for those wanting to reduce complexity and maintenance while keeping a complete platform.

It is not a choice aimed at maximum road range, nor at achieving very close gear steps: here the priority is continuity of use across mixed terrain.

Frame and platform

The Reynolds 725 frame retains the same logic as the rest of the range: durable structure, predictable handling, and strong ability to absorb surface irregularities, especially over medium to long distances.

The Amplitude G100 chromoly fork maintains an interpretation consistent with the platform: less focused on weight reduction than the carbon fork version, but more aligned with robust and direct use, even on less regular surfaces.

The presence of front and rear thru-axles, together with configurable internal cable routing, defines an updated and flexible platform. The ability to integrate a dropper post or dynamo systems with ease further clarifies the intended use of the model: real-world riding on variable routes, not just “linear” gravel.

Build and technical choices

The Shimano GRX 1×12 drivetrain (RX822 / RX610) with 40T chainring and 10-45T cassette is the central element of the model. The single-chainring choice reduces complexity and improves drivetrain management in dirtier or more technical sections, where pedalling continuity matters more than fine gear spacing.

This is not a “simpler” solution in a reductive sense, but a configuration that is more coherent with variable gravel use and less regular routes.

The Shimano GRX RX610 hydraulic braking system with 160 mm rotors maintains modulated and consistent braking, suitable both for light sportive use and for loaded setups.

The Amplitude G100 wheels with thru-axle standard and Center-Lock interface sit within a modern and robust platform. The 26 mm internal width works effectively with 45 mm tyres, contributing to stability and comfort on uneven surfaces.

Wheels and tyres / compatibility

The stock setup includes Maxxis Rambler 700x45 mm tubeless-ready tyres on pre-taped Amplitude G100 rims, with valves included. The choice is coherent with the bike’s real-world use: good rolling efficiency on tarmac, but with enough volume to handle dirt, gravel, and variable surfaces.

The platform supports tyres that are wide for a gravel bike, while maintaining a mixed-surface interpretation rather than moving into extreme off-road territory. The tubeless setup is an integral part of the bike’s logic, especially for long rides or discontinuous surfaces.

When it makes sense

When it does NOT make sense

Size guide

These height indications are a general guide based on stature. We can help you interpret geometry and riding position to choose a configuration aligned with real-world use: info@bikejamming.it.

For sizing advice, send us your height + inseam: reply within 24 hours.

Genesis Croix de Fer 40 FAQ

Technical specifications

Geometry

Pre-order consultation