Argon 18 Anti Matter review: Tested in the wind tunnel and on the trail

"What bike is that? It looks unreal!"

This was generally the kind of Instagram message I received whenever I shared a photo of the Argon 18 Anti-Matter during my test period. People were, at the very least, definitely on board with the aesthetics of the Canadian’s brand's new gravel race bike.

According to the Department of Energy, 'Antimatter is the twin of almost all the subatomic particles that make up our universe'. The scientists at CERN make Anti Matter to test; has Argon 18 meddled with the very fabric of the universe to bring us this new bike?

Bad science jokes aside, the Anti-Matter was spotted at the Traka at the start of May this year, and officially released later that month. It slotted in as Argon’s fastest gravel race bike and, in the brand’s words, is "built for the fastest gravel races on the planet."

Competitive gravel races are fast now. Very fast. In fact, for any rider, a gravel race is generally an exercise in putting out the most power you can for prolonged periods of time. As a result, the bikes are getting more specific and more speed-focused to try and bring those power requirements down.

The Anti Matter was developed from the ground up to be aerodynamic as a system. The brand claims over 800 hours of CFD (computational fluid dynamics) and 45 hours of wind tunnel testing went into its development. One line that stuck out to me from the press material was "achieving road bike level efficiency on gravel terrain."

This Anti Matter and the Nitrogen Pro road models could be a matching pair; you can see a lot of the same design language across both bikes.

If nothing else, that tells us something regarding what the Anti Matter is about. It’s also produced in a pretty mean-looking bike, which always helps.

The Anti Matter is available as a frameset, and in three SRAM XPLR builds in Rival, Force and Red. I tested the middle-spec Force-equipped bike out this summer after we took it to the Silverstone Sports Engineering Hub wind tunnel to see if it was as fast as it looked.

Design and aesthetics

The Anti Matter appeals immediately. The narrow headtube, chunky fork crown, big down tube and dropped, angular chainstays all work together to produce an aggressive and aesthetically pleasing frame silhouette.

Pair that frame with a pair of deep, wide wheels in the form of the Zipp 303 XPLR S, aero chainring and that eye-catching black and blue fade paint with lurid neon decals, and you have a fantastic-looking package.

The neon on the ‘sea foam/neon’ paint scheme is an inspired choice. It’s the pick of the paintjob bunch for me and really brings the whole look together.

There are small flourishes dotted across the frameset, from the chequered flag-type logos on the forks and chainstays to the little easter egg behind the fork crown, which is the equation for the power needed to overcome aero drag and road vibration.

Argon 18 has used its ‘pro-level carbon’ for the Anti Matter layup; it keeps the exact type to itself, though. In terms of design, the bike possesses the features a top-end race bike needs.

At launch, the brand claimed a 14.5 watt saving over the Dark Matter model at 45km/h (+/-15degree yaw); based on that, if you are racing and are focusing on performance and speed, this is the model to choose.

First up, the clearance number: the Anti Matter has 55mm tyre clearance, not quite class-leading now but still very healthy. The 1X-only, all-SRAM build options give it away, but the frame is UDH-friendly and is designed around a threaded T47 bottom bracket standard; there's also a 1 1/8in round steerer tube, aero bottle cages and a total of 12 mounting points, but no frame storage hatch; remember this is a race machine.

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The frame mounts are less 'attach your bikepacking bags' and more 'stick your Co2 canister here', or 'stick your aero top tube bag there'.

Altogether, there are two mounts on the top tube, some spaced for single items. Two under the top tube, four on the down tube, another two on the seat tube and a final two under the down tube. The mounts on the down tube can also be used to mount a specific WolfTooth 1x chain-guide, which is available separately.

A frame bag has been designed for the frame, and it comes included with all three models and the frameset; rejoice! It’s a collaboration between Apidura and ATTEN; Argon 18’s special projects arm dedicated to top-end components and products. It’s a sleek-looking thing, and fits neatly under the top tube; fitting it can be a slightly fiddly job so don’t leave it 10 minutes before your gravel race to whack it on.

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Argon 18 has also made some strong spec choices that in some cases feature on all three Anti Matter models and help strengthen the build. All three models have CeramicSpeed SLT headset bearings, and come with Schwalbe G-One RS Pro tyres in a 45mm size. The Force and Red-equipped bikes come with CeramicSpeed T47 BB Alpha units, the brand's top-spec bottom bracket.

The Force XPLR version arrives with 170mm crank arms, with a left-hand Quarq power meter and 1x 44-tooth aero chainring (you can fit up to a size 52T). There’s a 10-46T cassette and 160mm rotors fitted to the Zipp 303 XPLR S wheels.

The top-spec bike gains the XPLR SW wheels, which share the same dimensions but get an upgraded hub, and some surface texturing. On the wheels, there is a healthy-sized approved tyre list, which is worth checking so you know what you can run.

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The finishing kit is Argon 18’s own; there’s an integrated ATTEN CHB-01 handlebar, the same one that can be found on the Nitrogen Pro aero race bike. Available in 12 sizes, my 38cm / 100mm stem version measured 43cm at the drops, and has a reach of 75mm and a drop of 125mm.

Proprietary side-load bottle cages integrate seamlessly with the frame tube profiles, and the bar tape deserves a mention; it’s from Ciclovation and was both thin and grippy. I loved it. At the back, a 20mm setback aero seatpost, paired with a Repente Quasar 2.0 saddle, completed the build.

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I tested a size medium bike, which is given a ‘54-56’ label, quite the span. For me, this bike is closer to a 54 than it is a 56; check if you will need a size M or L if you are a taller rider.

Stack for an M is 555mm, whilst the reach is 392mm.

Compared to the brand's Dark Matter bike, it's clear this is a racier model; the chainstays and overall wheelbase are shorter. Whilst the seat tube angle is almost the same, the Anti Matter's head tube angle has been steepened up.

Compared to a Crux 5? The two bikes have very similar geometry; an M Anti Matter and a 54cm Crux 5 have the same chainstay length, fork rake and bottom bracket drop numbers of 425mm, 51mm and 78mm respectively.

The head tube angles are within 0.2 of a degree of each other, whilst the Anti Matter has a half-degree slacker seat tube angle; it has a shorter overall wheelbase too.

My test machine arrived slammed, with the bars sat directly on top of the bearing top cover. Well done Argon 18 for not leaving a huge stack of headset spacers in place on a bike like this.

I was sceptical of the layback seatpost before I rode the Anti Matter. I’m a big fan of inline seatposts and think they contribute to more comfortable modern positions as well as racier ones.

The brand told me the geo had been designed around a layback post, though you can get hold of an inline should you desire.

There aren't any hidden surprises regarding the geometry; the bike may start to feel a little slower with a big long stem up front, but that's never an issue for me. It's a fast, performance-focused setup without going completely nuts.

I was pleasantly surprised on my opening ride to find the bike didn’t feel how I thought it would. I felt locked in and comfortable, not too stretched out as I feared. The 73.5 degree seat tube angle, 100mm stem and 51mm fork rake all help to put you in the right place.

Handling-wise, I feel the 100mm stem helped keep things nippy. I rarely need a stem over 100mm, and on a bike like this, I think it aided the steering. This is still a gravel bike, and things didn't feel too long or cumbersome; I could swing the bike into turns and still have fun.

Performance

The Anti Matter feels absolutely rocket-ship fast, particularly in faster gravel or off-road sections. Even on my first ride, I mouthed to myself ‘this is rapid’ on a fast and flowy dirt section that requires a quick shimmy as it traces an S through my local woods.

Why does it feel fast? The bike picks up speed instantly, and if the surface is smooth, that combination of the stiff bar and frame, 44-tooth chainring, aero Zipp wheels and the fast Schwalbe tyres means it does indeed feel road bike fast off-road.

This feeling of speed, and the bike urging you to press on, is a key theme of the Anti Matter. It’s one of those bikes that makes you want to drop the hammer, and it feels great to do so.

I value a gravel bike that can handle itself down a rough descent. On rough terrain, I felt some harshness from the bike and felt quite a lot of feedback via the ATTEN integrated handlebar. The bike is a good descender, and handled my technical test descents well, but it is a harsher experience.

The ability to hammer rough, rocky descents probably wasn’t a key aim during the Anti Matter design process, but if this is something you enjoy in your own gravel riding, the Dark Matter would probably be a better bike to go for.

SRAM’s XPLR groupsets rule the roost when it comes to gravel equipment, and Force is excellent; it’s slightly heavier than Red, but the brakes are just as powerful. That 44-tooth ring worked for me, and the bike's fairly low overall weight of 8.3kg helped when climbing (the Red-equipped model will be lighter still), but it would be easy enough to purchase a few alternate rings to suit your racing or riding. The groupset hasn’t missed a beat, and is a fantastic choice for any gravel bike right now.

The Zipp 303 XPLR S wheels with their 32mm internal width are at their best on faster, smoother terrain; get the bike moving on road sections or gravel, and it really flies. They aren't a magic bullet, though; their 32mm inner rim profile and skinny rim sidewalls can be susceptible to rock smashes, especially when running narrower tyres at low pressures.

They are all-rounders with the right tyres, but in my experience they are at their very best on faster, smoother terrain and with 45mm + rubber fitted.

Rattling down rocky, rough trails is at the harsher end of the spectrum, but everywhere else the Anti Matter feels racey, stiff and exciting. There is balance there; however, the steering isn't so sensitive that it's frantic, and it wasn't so stiff that it left me wanting to stop.

Wind tunnel testing

Thanks to our recent gravel bike wind tunnel test session, we have a set of aero data for the Anti Matter, helping to paint a clearer picture regarding its aero credentials.

We tested the same bike I’ve tested here, and it performed very strongly against a crop of the latest and most popular racy gravel bikes.

We carried out bike-only testing, as well as test runs with a rider. After all, you never see a bike racing on its own, do you?

Our test runs were all completed at 35 km/h, and across seven yaw angles from -15° to +15° in 5° increments.

Long-time followers of Cyclingnews' wind tunnel testing should by now be familiar with our trusty Trek Emonda baseline test bike; we use this as the baseline for all of our tests, so that we have a reference point for how fast every bike we test is.

Included below are two new graphs showing how the gravel bikes in our test group performed against the baseline so we can compare them.

In the bike-only stock build test, the Anti Matter topped the test group. For the full breakdown of the test day, head to our in-depth gravel bike aero test.

We tested with a rider too; CN Associate Editor Josh Croxton rode each bike and held a standard 'in the drops' position for each capture in the tunnel.

The Crux 5 took the top spot with a rider, followed by the Wilier Rave SLR, and then the Anti Matter. However, our error margin meant those bikes, along with the Reap and Dogma GR, could also claim the top spot; there was only a couple of watts in it.

We also tested the bike with the frame bag fitted and found a 0.75w saving (tested as bike only). So although the difference is small, you're probably better off using it, even if it's empty.

Our own testing showed the Anti Matter is a highly competitive gravel machine and that its aero frame design backs itself up in testing.

In the real world, the individual rider, their position on the bike and tyre choice and pressures need to be optimised to make potentially huge gains, but it’s clear that the Anti Matter is putting you in a competitive place straight away.

Maintenance

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There shouldn’t be any nasty surprises when it comes to living with the Anti Matter. In fact, the stock headset and bottom bracket choices should help boost longevity.

The CeramicSpeed SLT headset bearings and Alpha BB both have lifetime warranties and have long service intervals. The SLT headset bearings were designed as a response to integrated front ends creating headset issues.

CeramicSpeed lists a service interval of 8,000–13,000 km (5,000–8,000 miles) for its BB Alpha, and a once-per-year service for headset bearings. CeramicSpeed recommends using specific products on them; make sure your shop doesn't fill your $300 BB with any old grease. Look after them properly, and they should look after you.

Elsewhere it's business as usual. Threaded bottom bracket, easy to service Zipp hubs, and you will need to periodically remove and regrease the frame hardware, seatpost, etc.

One point I really liked was the thru axles having the thread pitch specs written on them. It can be difficult to find the right thru axle in a bind, and it's a useful touch for the future.

Value

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In this spec, the Anti Matter Force costs $8,999 / £7,900 / €8,995.

In context, things could be worse. I'd say the pricing is in line with plenty of other Force-equipped performance gravel machines in this price bracket, and if you are shopping, there's plenty to choose from.

I'll compare it to its nearest two competitors in our wind tunnel test for a start. One thing I will say now is I suspect that this will be a popular bike; it's been well received, and though we all have different tastes, I see riders wanting one.

A top-level S-Works SRAM Red Crux 5 comes in at $14,000; that's another price bracket.

The Anti Matter Force sits between the new S-Level Crux 5 (2nd tier frame but Red XPLR spec), and the Expert model (2nd tier frame, SRAM Force XPLR spec). The Crux 5 Expert sits at $6,995, but it has a two-piece bar and stem, and arguably less exciting Roval Terra C III wheels. It's also about the same weight.

A Wilier Rave SLR iD2 with Force XPLR comes in at $9,200 or $7,200 (no power meter), depending on the spec, with Miche carbon wheels. I see no weak spots in the spec of the Anti Matter; Force XPLR is great, the BB and headset bearings have been upgraded, and the bike comes with the frame bag. Things could be worse.

Verdict

The Anti Matter is a great-looking gravel race bike that feels absolutely rapid to ride. It has backed the on-bike, real-world experience up with a very competitive performance in our own wind tunnel testing.

Its focus is speed, and it’s best when you're pressing on smoother, faster gravel surfaces. I found it started to get a bit chattery and harsh when hitting rougher stuff at speed, but for everything else, it’s a rocket ship.

I could get aero, but the geometry let me find a comfortable position, which let me have fun in the rough stuff and hook into the drops for the techy stuff.

For me, it looks great, and rides brilliantly without being a one-trick pony that's only capable of being pointed in a straight line.

The mad scientists at Argon 18 have created their own form of Anti-Matter that is guaranteed to convert all of your energy into forward momentum.