Depending on who you ask, disc brakes are either (a) the best and most exciting technology to happen to road bikes for years or (b) completely unnecessary – they’re ugly, heavy and we could stop just fine before they came along, couldn’t we?
For the record, I began as a ‘b’ but it didn’t take long before I reached the fence, sat on it for a while, then fell off on the ‘a’ side, never to look back.
The facts are hard to dispute. Discs bring numerous benefits to road bikes and, believe it or not, better braking is actually not top of that list, nor possibly the second or even third. Canadian brand Argon 18’s latest Nitrogen Disc is proof of that, as R&D director Martin Faubert attests.
Holistically better
‘Far from being something we had to work around and accept compromises over, disc brakes actually afforded the new frame and fork several crucial performance improvements,’ Faubert says.
‘The disc fork, new carbon layup and 12mm thru-axle resulted in an 80% increase in front end lateral stiffness [versus the 2018 Nitrogen Pro], making the bike more responsive in sprints and on climbs while eliminating front brake rub. Torsional stiffness improved too, delivering better out-of-corner acceleration, and we were able to retain the same comfort level.
‘We discovered the aerodynamic cost was less than 2 watts at 45kmh and 0° yaw, and had zero impact at yaw angles higher than 5°,’ Faubert adds. ‘A lot of this is because removal of the rim brake allows better airflow around the junction between fork and down tube.
‘Tyre clearance has also been widened to 30mm, which gives the bike more versatility, with added grip and potential to further enhance comfort. All this is before we’ve even mentioned more effective braking in all weather conditions. We couldn’t see any inconveniences. Disc brakes are definitely the way of the future.’
It almost goes without saying that, from now on, Argon 18 will no longer be offering a rim brake version of the Nitrogen.
Pro ratified
The aero-focussed Nitrogen first appeared in 2015, and the Nitrogen Disc made its debut at the tail end of 2018 in the hands of a select few pro riders at Astana.
By the time you read this, it will likely have been wheeled out as the weapon of choice for the flatter stages in the first week of the 2019 Tour de France. Maybe the brand’s countryman, Canadian Hugo Houle, might even have chalked up some TV time on one in the early breaks.
Having tested several of Argon 18’s other models and always found them to deliver adept ride quality, my expectations were high for the Nitrogen Disc. Some bikes take a bit of time to get to know and tease out their best attributes, while others just set out their stall immediately.
The Nitrogen Disc is an example of the latter. I knew within just a few kilometres on my first outing that I was in for a fast, if a little rough, ride.
The frame’s stiffness immediately resonates, be it cranking up to speed or grinding up a steep incline. The steadfastness of the frame in combination with its low weight – claimed 948g frame (medium, painted) and an impressive 7.37kg complete – translates into a punchy ride feel and extremely responsive handling.
I would go so far as to say the Nitrogen Disc is as eager to react and as precise in its tracking as any bike I’ve tested.
On one particular steep descent on one of my regular test loops my fingers instinctively went for the brake levers to scrub speed at the usual point, but on this bike I found I was able to hold off a fraction longer, carrying more pace through the turn, but all the while feeling completely confident in doing so.
Royal rumble
Speed on rolling and flatter terrain undeniably comes with ease, especially aided on this test bike by the excellent Zipp 404 Firecrest wheels that not only back up the lateral rigidity of the frame during accelerations but also hold their speed appreciably well.
There were days during testing when the south coast, where I live, was being battered by strong winds, and the Nitrogen Disc impressed me with how deftly it sliced into a tough block headwind. At the same time it didn’t feel like being aboard a rodeo bull in strong side gusts. Once more a nod to the wheels in this regard, too.
The surfaces in the New Forest and surrounding areas, where I spent the most time riding the Nitrogen Disc, aren’t exactly silky smooth. They’re more like one long rumble strip, scarred by the subterranean growth of a million tree roots, and that’s before I get round to mentioning the numerous cattle grids.
It was here that I felt the Nitrogen Disc maybe lacked a little refinement compared to the very best bikes I’ve ridden in this category.
It’s certainly not a punishing ride, but it’s also not as forgiving as some competitors that I’d say are at least as fast but just that bit more accomplished at dampening vibration. A few years ago I would have been willing to accept that you can’t have lightning fast and a cushy ride feel together.
However I now know, through first-hand experience, that there are brands that have successfully debunked that. But that’s only a slight tarnish on an otherwise highly polished ride feel.
The Nitrogen Disc is a really good aero race bike, but to be considered in ‘dream bike’ territory I’d want it to be just a little more comfortable. But hey, maybe that’s just me getting soft in my old age?
Spec
| Frame | Argon 18 Nitrogen Disc |
| Groupset | Sram Red eTap HRD |
| Brakes | Sram Red eTap HRD |
| Chainset | Sram Red eTap HRD |
| Cassette | Sram Red eTap HRD |
| Bars | Zipp SL70 Aero |
| Stem | Zipp SL Speed |
| Seatpost | Argon 18 carbon aero |
| Saddle | Selle San Marco Mantra CFX |
| Wheels | Zipp 404 Firecrest, Panaracer Race A Evo 3 25mm tyres |
| Weight | 7.37kg (medium) |
| Contact | zyrofisher.co.uk |
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