Argon 18 has launched the Anti Matter in response to the increasing speeds at gravel races. First spotted at the Traka last week, the Anti Matter slots into the brand’s gravel range as its aero-focused race bike, and Argon 18 says it improves aerodynamic efficiency by 14.5 watts at 45kmh over the brand’s Dark Matter adventure gravel bike.
The new gravel race bike borrows elements from Argon 18’s 2025 aero road bike, the Nitrogen Pro. This includes sharing the same cockpit and seatpost as its road contemporary, as well as a similar carbon composite blend.
For tackling the rigours of gravel, a generous 55mm clearance has been incorporated into the aero frameset. There’s no down tube storage, but there are aero bottle cages, a set of bespoke Apidura bags and 1x-only compatibility.
The Anti Matter is available as a bare frameset for £4,395/€4,995 and in three specs, from SRAM Rival XPLR AXS to Red XPLR AXS, with prices ranging from £5,495/€5,995/$6,499 to £10,495/€11,995/$12,999.
Evolution from the Nitrogen Pro
The Anti Matter is a new aero gravel bike for Argon 18’s range, which includes the adventure-focused Dark Matter. The bike’s development stemmed from a need to respond to the increasing speeds in modern gravel races.
‘We’ve seen increasing racing speed in gravel events over the past few years, especially in the major European and North American series,’ Argon 18’s product director Alexandre Côté tells Cyclist. ‘It’s an improvement of over 30% in some cases in comparison to where the races were in the late 2000s and 2010s.
‘The Dark Matter, Grey Matter and Krypton just don’t meet the requirements of modern gravel racing in some cases. So our approach was to add a no-compromise gravel race bike to deliver the pro-level road efficiency, but on an optimised system for dirt.’
With that road-level performance in mind, the Anti Matter was developed alongside the Nitrogen Pro, released last autumn and ridden this year by the Novo Nordisk UCI ProTeam. That means the Anti Matter benefits from several aesthetic and component innovations first rolled out on the Nitrogen Pro last year.
To that end the Anti Matter uses a similar carbon composite blend as the Nitrogen Pro to help achieve the same bottom bracket and head tube stiffness from its performance road model.
The frameset weighs a claimed 1,050g in a medium size, which is just 125g heavier than the equivalent Nitrogen Pro frame. The Anti Matter’s weight grows to a claimed 8.1kg for a complete build in the SRAM Red spec.
14.5 watts more efficient than the Dark Matter
Like the Nitrogen Pro, aerodynamics were a key focus in developing the Dark Matter.
Argon 18 says the new gravel bike underwent 45 hours of wind tunnel sessions and over 800 hours of CFD computer testing. During that time, the brand tested 130 tube profiles to help finalise the frameset’s design.
The result is a 14.5-watt saving over the brand’s previous top gravel model, the Dark Matter, at 45kmh.
Though the additional tyre clearance at the fork stops the Anti-Matter’s front end from being identical to the Nitrogen Pro, the gravel bike pinches its road sibling’s Atten CHB-01 handlebar. As such, the aero advantage is the same, with Argon 18 claiming the bar to be 6.7 watts more efficient than a competing two-piece system (at 45kmh).
The stem is offered in six lengths, ranging from 80mm to 130mm. There are two options for bar width: 360mm and 380mm. In a 380mm wide bar with a 100mm stem, the one-piece component weighs 320g according to the brand.
Argon 18 says the intent was to go ‘as narrow as possible within the UCI regulations’ in anticipation of the governing body’s new handlebar width rules. That aero focus influenced the choice to employ a slight flare to bars.
Like on the Nitrogen Pro, the cockpit can only be used with wireless groupsets as the bars are too narrow to accommodate any wires. This is said to be a ‘conscious decision for pure performance gains and size optimisation’.
55mm clearance and short chainstays
The Anti Matter’s stack and reach are the same as the Nitrogen Pro, coming in at 555mm (stack) and 392mm (reach). Compared to the Dark Matter, this is a 27mm reduction in stack and 14mm reduction in reach.
The chainstays have also been designed to be as short as possible within the limitations of SRAM’s guidelines and the tyre clearance. The Anti Matter’s chainstays therefore measure to 425mm, a 9mm decrease from the Dark Matter, with the seat tube offset relative to the bottom bracket to create radial clearance for large tyres.
The bike is specced with 45mm-wide tyres, but it can accommodate tyres up to 55mm.
‘A 55mm clearance for a pure aero gravel racer is impressive,’ Côté says. ‘The wider you go, the softer the front end in particular gets. You then have to reinforce it, and a weight penalty comes into play. So we went as wide as we could to find that sweetspot between aero, stiffness and weight. It was a very conscious choice to go to that specific width and angle for the blades. They’re actually angled inwards to push the airflow outside of the rider’s legs in order to move the airflow outside the body as much as possible.’
Elsewhere, the bike uses the same D-profile seatpost and partially horizontal dropped seat stays as the Nitrogen Pro, said to improve aero efficiency and compliance. The chunky bottom bracket is slightly different however, as Argon 18 adds an oversized CeramicSpeed T47 bottom bracket for improved power transfer.
1x only
The Dark Matter has forgone the front derailleur mount altogether, meaning the full range is only 1x compatible. Argon 18 has indicated that this choice may become more prevalent in performance gravel bikes across the industry.
‘We made a clear choice not to be 2x compatible,’ Côté says. ‘With a new platform, there is room to accommodate what’s coming in terms of innovation. Right now, the momentum across major gravel manufacturers is to completely ditch 2x in favour of a 1x system with more flexibility and optionality for the rider. 2x just doesn’t give the same usability or the same safety in a race that a 1x system does.’
‘Knowing that the SRAM XPLR setup was coming soon, it was a clear statement to go with a 1x-specific design. Going in that direction also maximises tyre clearance and the aero performance. There’s a penalty to a 2x setup with the front derailleur and chain rings in terms of both aero and weight. Our choice also helps to optimise the stiffness in the bottom bracket area. The fewer holes and things you have to drill, the more you can optimise your layup.’
The SRAM Red and Force specs will come with an aero chainring on the crankset. To further improve chain performance across the range, a custom-made chain guide will also be available. The guide, designed by Wolf Tooth, can be screwed into the mounting points on the down tube by the bottom bracket.
Aero bike bags and bottle cages
While the Anti Matter strips out the Dark Matter’s down tube storage space to save on stiffness and weight, bag brand Apidura has come on board to provide a frame bag that screws into the top tube behind the head tube.
That frame bag will be included in all Anti Matter builds, but a narrow ‘bento box’ bag will also be released and available aftermarket.
The brand insists the bags bring ‘no aero penalty’ due to their streamlined design, and Argon 18 also underlines that the bags offer ‘better ergonomics and access than internal storage’.
Like the Nitrogen Pro, the bike comes with side-loading bottle cages, which were designed specifically for this frameset to minimise wind turbulence. To meet their shape, the bike’s down tube fluctuates in order to create a seamless connection to the cages, leading to a wide bottom bracket for improved stiffness.
Anti Matter spec options and prices
The Anti Matter is available now. There are three spec levels and colourways, all offered with SRAM groupsets. Prices vary between £5,495/€5,995/$6,499 and £10,495/€11,995/$12,999 for the top build, which comes with SRAM Red XPLR AXS, Zipp 303 XPLR SW wheelset and Schwalbe G-One RS Pro tyres.
The frameset will be available to buy on its own for £4,395 from December 2026. This price includes the frame, fork, seatpost, headset and cockpit.
Argon 18 Anti Matter SRAM Red
- Groupset: SRAM Red AXS XPLR
- Gearing: 44t, 10-46t
- Wheels: Zipp 303 XPLR SW
- Tyres: Schwalbe G-One RS (45mm)
- Saddle: Repente Quasar
- Price: £10,495/€11,995/$12,999
Argon 18 Anti Matter SRAM Force
- Groupset: SRAM Force AXS XPLR
- Gearing: 44t, 10-46t
- Wheels: Zipp 303 XPLR S
- Tyres: Schwalbe G-One RS (45mm)
- Saddle: Repente Quasar
- Price: £7,900/€8,995/$8,999
Argon 18 Anti Matter SRAM Rival
- Groupset: SRAM Rival AXS XPLR
- Gearing: 40t, 10-46t
- Wheels: DT Swiss G1800
- Tyres: Schwalbe G-One RS (45mm)
- Saddle: Repente Quasar
- Price: £5,495/€5,995/$6,499