Argon 18 Dark Matter GRX Bike

$3,899.00

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Coming soon! Reserve your Argon 18 Dark Matter GRX Bike today and a sales associate will contact you within 24 hours with the shipping date.

SKU: DM.XXS.373A.3.1 Option: Anthracite / XXS

Stock Availability by Location

RA Cycles Brooklyn — Out of stock

105 5th Ave, Brooklyn, NY 11217718-636-5242

RA Cycles Walnut Creek — Out of stock

2099 Mt Diablo Blvd, Walnut Creek, CA 94596925-433-7099

Distribution Center - East — Out of stock

Distribution Center - Central — Out of stock

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Argon 18 Dark Matter GRX Bike Info

The Argon 18 Dark Matter GRX Bike is built for riders who take gravel seriously — not as a weekend novelty, but as a discipline that demands its own geometry, its own carrying capacity, and its own kind of confidence. Argon 18 has a long history of building performance road and triathlon bikes, and the Dark Matter applies that same engineering rigor to terrain that rarely follows a plan.

The carbon frame is shaped around an adventure-first geometry — a taller head tube, considered fork rake, and a longer wheelbase than you'd find on a race-oriented gravel build. On loose descents or unfamiliar tracks, the handling stays planted and predictable, the kind of stability that actually matters when you're far from a trailhead and the surface underneath you keeps changing. Clearance for 700×57mm tires gives you genuine flexibility across surface types, from compacted gravel to rougher backcountry two-track, without compromising the frame's responsiveness when you want to push the pace.

What distinguishes the Dark Matter in a crowded carbon gravel field is its integrated in-frame storage system. Compartments built into the frame itself — combined with an extensive network of mounting points across the fork and frame — mean you can carry tools, spares, layers, and nutrition without strapping on aftermarket bags that upset the bike's balance or aerodynamics. The Shimano GRX drivetrain rounds things out: a gravel-specific groupset designed for mixed-terrain shifting, reliable under load, and tuned for the kind of wide-range gearing that long days in the dirt actually require.

Design Benefits

  1. Adventure Geometry That Earns Your Trust: The Dark Matter's longer wheelbase and taller front end create handling that feels deliberate rather than nervous on loose or unpredictable surfaces. When you're three hours into an unfamiliar route, that composure isn't a luxury — it's what keeps you riding confidently rather than managing the bike.
  2. Serious Tire Clearance for Real Terrain: Support for up to 700×57mm tires means the Dark Matter isn't limited to hardpack gravel. Wider rubber absorbs rougher surfaces, improves traction in soft or wet conditions, and opens up routes that narrower gravel bikes simply can't handle. The frame is designed to accommodate that range without sacrificing stiffness or pedaling efficiency.
  3. Integrated Storage That Changes How You Pack: Most gravel bikes force you to choose between external bags and a clean setup. The Dark Matter's built-in frame storage resolves that tension — compartments designed into the frame keep essentials close and the weight centered, so the bike handles consistently whether you're loaded for a long day out or running light on a fast loop.
  4. Shimano GRX Drivetrain Built for Mixed Conditions: GRX isn't road components adapted for gravel — it's a groupset developed specifically for it. The lever shape, the derailleur geometry, and the gear range are all calibrated for the kind of varied terrain the Dark Matter is designed to cover. Shifting stays positive and predictable even when conditions get rough or the chain is under load on a steep climb.
  5. Mounting Versatility for Every Configuration: An extensive set of frame and fork mounting points means the Dark Matter adapts to how you actually ride — whether that's a minimalist setup with just a couple of cages, or a fully loaded configuration with racks and bags for multi-day routes. The bike was designed to carry gear without being defined by it.

Final Take

The Dark Matter is for the rider who wants a carbon gravel bike that doesn't ask them to choose between performance and capability — one that handles technical terrain with assurance, carries what you need without compromise, and runs a drivetrain purpose-built for the discipline. If your rides regularly take you far from pavement and you want a bike that was designed with that reality in mind, the Dark Matter is a considered choice.

Argon 18 Dark Matter GRX Bike - Specifications

Frame Material:
Carbon
Fork:
Carbon
Headset:
Integrated
Seatpost:
Argon 18 TDS-C
Rear Derailleur:
Shimano GRX RX822
Crankset:
Shimano GRX RX610
Chainrings:
40t
Bottom Bracket:
Token T47 24mm
Brake Calipers:
Shimano GRX RX400 Hydraulic Disc
Rotors:
Shimano RT70 160mm
Shifters / Levers:
Shimano GRX RX610
Cassette:
Shimano SLX M7100 12-speed 10-51
Chain:
Shimano M7100 12-speed
Wheel - Front:
DT Swiss G1800
Wheel - Rear:
DT Swiss G1800
Stem:
FSA SMR-II
Handlebar:
FSA A-Wing Pro AGX
Saddle:
Repente Quasar S 2.0
Tires:
Vittoria Terreno T50 Mixed 700x50
Pedals:
Not Included

*Specifications are subject to change.

Argon 18 Dark Matter GRX Bike Geometry

Argon 18 Dark Matter GRX Bike Geometry
Size:XXSXSSMLXL
B. Seat Tube (c-t)420435460495540585
C. Top Tube Length507530553577602629
D. Head Tube Length72-9587-112106-131126-151151-176178-203
E. Chain Stay Length436436436436436436
F. BB Drop808078787676
G. Seat Tube Angle75.574.974.373.773.172.5
H. Head Tube Angle68.57070.5717171
I. Stand Over Height713729755786825863
J. Wheel Size700c700c700c700c700c700c
K. Stack520-543540-564561-585582-606603-627629-653
L. Reach361-370373-382386-394398-406410-418422-430
Stem Length60mm70mm80mm90mm100mm110mm
Bar Width42cm42cm42cm42cm42cm44cm
M. Crank Length160mm165mm170mm170mm172.5mm172.5mm

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