Ridley ASTR RS GRX800 DI2 2x / UD Carbon/Crocodile Green S / UD Carbon/Crocodile Green

Race-Hard in Dirt Action: The Ridley ASTR RS GRX800 Di2 in Crocodile Green

As a performance-driven gravel bike, the ASTR RS was built specifically for modern gravel racing – evidenced by the groundbreaking 52 mm tyre clearance and a geometry that inspires confidence at high speed. This version brings an electronic Shimano Di2 drivetrain and the striking Crocodile Green look to the start line for riders who leave nothing to chance in dirt competition.

The manufacturer delivers insights into the bike in its official bike-check: the film walks through the ASTR RS step by step – fittingly in the Crocodile Green paintwork. You will find the video here on YouTube: https://www.youtube.com/watch?v=nGj7TtzOjKk

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The foundation is a frame of ultra-high-modulus carbon from the Elite Series that weighs only about 890 grams in size M and underlines the race-oriented ambition of the platform. Aerodynamically profiled tubes and a fork with an integrated crown diffuser, derived from the Falcn RS aero-to-weight study, measurably reduce drag. Setting the pace is the electronic Shimano GRX800 Di2 system in a 2x12 layout: the GRX 820 crankset with 48/31 teeth and an Ultegra 11–34 cassette produce 24 gears; shifting and braking via Di2 technology are precise, smooth and dependable even in dirty conditions. Lighting is absent – true to the competition mindset, there are no lamps and no dynamo routing. The number of mounts is also deliberately low; for ultra-distance races, however, the aerodynamic Apidura aero-pack mounting points are available, adding storage without disturbing the drag profile. Other highlights include the integrated Forza Nimbus Pro cockpit in Stealth Black, the D-shaped Forza Aero seatpost, the deep DT Swiss GRC1600 wheels with 42 mm rims and the 47 mm Vittoria Terreno Dry tyres with tan sidewalls.

The name in focus: ASTR, RS, GRX800, DI2, 2x and Crocodile Green

ASTR is the family name of the platform, pronounced "ASTor" rather than "ASTRa"; no official long form exists, though the Latin "Aster" (star) resonates. The RS officially stands for "Racing Sport" according to the maker and marks the race variant of the family. GRX800 names the drivetrain tier: "GRX" is the gravel series of the component maker, the digit the high, here electronic level. DI2 is its electric shifting technology, "2x" reveals the double-chainring layout. UD Carbon refers to the visible unidirectional carbon finish, Crocodile Green to the vivid green shade of the paintwork – and the XS at the end simply denotes the frame size.

Series comparison: how this ASTR RS stands out from other builds

Inside the ASTR family the RS sits at the top: the base ASTR uses a cheaper carbon layup, a round seatpost, a conventional stem-and-bar setup and also accepts mechanical groupsets, whereas the ASTR RS relies on ultra-light carbon, an aero seatpost, the integrated Nimbus Pro cockpit and electronic drivetrains only. Among the RS builds themselves, the main differences lie in the drivetrain: this configuration runs Shimano GRX Di2 in 2x mode with a front derailleur and offers the classically wide gear spread for climbs and flats, while the SRAM siblings rely on a single chainring (1x) and an enormous cassette. Visually, the Crocodile Green finish stands out too, and the E-ASTR follows a completely separate path as the electrically assisted family member with its TQ motor.

Purpose: why this gravel bike is built for fast dirt racing

This machine belongs in rough race practice: gravel competitions such as Unbound, Big Sugar or the Traka 360 demand speed, ruggedness and reliability in equal measure. That is exactly what the ASTR RS is engineered for – the blend of a lighter frame, optimised aerodynamics, wide tyre choice and a stable geometry (long wheelbase, lower bottom bracket, slacker head angle) carries riders into the finale with more energy stored than the opposition. Compared with the Kanzo Adventure, which with rack mounts, lighting options and a relaxed position is aimed at bikepacking and touring, this bike stays consistently performance-focused: it wants to go fast rather than carry loads. It also sharpens aero and tyre clearance versus the Kanzo Fast and the all-road Grifn RS; if you mostly plan loaded multi-day trips, the Adventure serves you better – if you chase seconds, you are right here.