EXT Aria Rear Shock

Extreme Racing Shox or EXT is an Italian suspension supplier with roots in motorsports, where the brand found success working with legendary racers like Sebastien Loeb who dominated the World Rally Championship for years aboard his Citroens. In 2014, EXT decided to try their hand at making products for mountain bikes as well, and brought over many of the technologies and the expertise they have been developing over the years. We have previously tested their excellent coil shocks with good results (links: Storia review and e-Storia review), so when the company introduced their first air shock we were keen to give it a spin as well. After 5 months on the trail with the all-new Aria, we’re here to report on our findings.

EXT Aria Highlights

• AS3 technology: dual positive chamber featuring only 2 dynamic seals to separate the 3 different chambers (EXT patented design)
• Positive chambers +/++ (low/high) with infinite adjustment potential via 2 separate air valves to finetune the spring characteristics
• Large volume, self-activating negative chamber
• Unique air seal design based on aerospace technology
• Lok 2.0 technology
• 14 mm superlight internal shaft
• Large 28mm main hydraulic piston
• Adjustable Hydraulic Bottom-Out Circuit (HBC)
• Proprietary “Super Finish” surface treatment on sliding parts
• Sizes: 210 to 250 mm length, 50-75 mm stroke (Metric Standard) // 185-225 mm length, 50-75 mm stroke (Metric Trunnion)
• Weight: 644 grams (as tested, 210x50, verified)
• MSRP: EUR 1060,00 € + VAT

Initial Impressions

When pulling the Aria from the box, you’re met with an impressive looking piece of kit. The finish is of very high quality, and the design is elaborate, with pleasing contours and shapes giving the shock a very well-rounded appearance. The large volume air can is quite imposing, as are the piggy-back damping tubes and reservoirs (check that there is space in your frame if you think there might be an issue). Would we wish for laser-etched graphics at this price point? Yes. Are the stickers OK though? Yes.

Beyond its good looks, the Aria delivers all the features you would expect from a high-end shock, and then some. Starting with the air spring, the Aria sports dual positive chambers and a self-equalizing negative chamber. The two positive chambers allow you to shape the spring curve, with the second chamber acting as an adjustable token, essentially. Want more ramp up towards the latter part of the stroke? Add pressure to the secondary chamber. Want a more linear shock? Reduce the pressure in the second chamber and add main chamber pressure to achieve the support needed. Adjustments need to be carried out with a special high-pressure shock pump, as the second chamber can require as much as 600 psi depending on your set-up (the pump is supplied with the shock).

On the hydraulic side, the Aria offers plenty of adjustments as well. You’ll find the classic high- and low-speed compression adjustments and a single rebound adjuster, but also an adjustable hydraulic bottom-out feature as well as a 2-position climb switch. Low-speed compression and rebound require a 4mm allen while the high-speed compression adjustment works with a 12mm open wrench (which is rather unusual). The HBC adjuster also works with the 4mm allen.

On The Trail

Setting up the Aria is a little bit more involved than a simpler shock, of course. To begin with, you need to figure out your spring rate, and EXT supplies a handy little guide for this. They provide the air pressures recommended to achieve a certain spring rate (as measured in lbs/in), which is a good place to start (if you don’t know your current spring rate, you can figure it out using a spring rate calculator like the one featured on EXT’s website for example). Note that most of these calculators do not take into account the progressivity of different frames, so you could end up some ways off the standard suggestions. In our case, we did find that we ended up running less pressure than suggested to achieve the desired behavior on our test bike, a 2023 Transition Smuggler with 130 mm of significantly progressive rear travel driving a shock with a stroke of 50 mm. Your mileage may vary, but you can still start with the recommended values and then adjust as necessary to arrive at the sag measurement and the riding characteristics you are after.

On the damping side, EXT also provides a set of guidelines to help you get going. We started off following their recommendations which left us with the HBC fully closed and the rest of the adjustments somewhere in the middle of the available range.

Out on the trail, we were quickly won over by the amount of comfort and control on offer. Even with some of our settings a bit off to start with, the Aria was both smooth and dynamic in action. EXT seems to have nailed the size of the self-equalizing, negative air chamber as the shock offers a great balance between small bump compliance and support out of the box. As we started experimenting with the main air pressure settings we soon came to appreciate just how much control the dual positive air chamber design provides. In the end, we landed somewhere close to the initial recommended value for the main spring, with about 15% less than recommended in the second (ramp-up) chamber. This provided for a ride that felt really close to the linear nature of a coil shock, without ever becoming overwhelmed by bigger hits, which matched up well to the progressive leverage ratio curve of the Smuggler. The hydraulic bottom-out control also deserves a call-out here, it provides a lot of poise during the end of the stroke, and it really helps keep things comfortable even when using all the travel.

We often find ourselves backing off a lot of the high-speed compression damping to achieve better compliance (on both shocks and forks), but this was not the case with the Aria. The EXT recommendations had us right in the middle of the available range of high-speed compression, and that’s where we’ve left it. We sped up the rebound by one or two clicks to get a bit more pop out of the bike, but other than that, we’ve been really impressed with how well the shock functions on the trail even with a significant amount of damping applied. Between the effective damping and the adjustability of the air spring the Aria really provides a wealth of tuning possibilities and it we can see it working well on a whole range of different frames, from progressive to linear.

The pedaling platform function of the Aria looks and feels similar to the one on the company’s coil shocks. It’s a small, two-position lever that engages a separate compression circuit when flipped. This forces oil to pass through a stiffer shim stack that increases the compression force required, thus helping mitigate bobbing and unwanted frame movement during climbs. The Lok circuit is equipped with a blow-off valve to avoid any potential damage should you forget to open it up again for the descent. On our test bike, the platform provided was enough to eliminate most of any bobbing, and it also helps hold the bike up a little bit higher in its rear travel, which is beneficial on the uphills. For reference, the lock-out effect is not as marked as a typical RockShox platform for example, but that also makes it slightly more usable on mellower trails (note that you can request to custom tune the lockout circuit if you want it to be stiffer than the standard version).

Things That Could Be Improved

This section will just be us nit-picking, as we don’t have any real criticism to offer up otherwise. The choice of a 12 mm open wrench for adjusting the high-speed compression is a little bit inconvenient, as this is not usually part of a multitool so it would have to be added to your arsenal as a separate item if you think you might be wanting to adjust your high-speed compression out on the trail (which probably doesn’t happen that often for most people, once it’s set…). We also think that the graphics could be laser-etched for an even nicer finish, but there is nothing fundamentally wrong with the stickers as is. You might also argue that the lock-out lever is very small and sits in a spot where it can be a bit harder to find when reaching for it while riding, but you’ll soon get used to it.

Long Term Durability

We’ve been riding the Aria fairly intensively for five months now, and there are no issues to report on so far. The shock has held air really well, and all the adjustments are working as they did on day one. Of the previous EXT shocks we’ve tested here at Vital, one has been going strong for a couple of years already, while another one did blow a seal in the damper but has been behaving since that was fixed. All told, we’re pretty confident that EXT’s stuff will last you a good while.

What’s The Bottom Line?

By combining the excellent damping and the bottom-out control of the company’s coil shocks with a highly adjustable, dual-chamber air spring, EXT has created one the most versatile high-performance air shocks we have tested to date. The spring curve can be shaped to suit your frame specifically, and the damping adjustments are effective and offer a good usable range. Many marketing departments will use the words “coil-like” when describing their air shocks, but in EXT’s case, we feel it’s actually justified – you can indeed set up your Aria to closely mimic the feel of a coil shock. But you can also make it very progressive, or settle for something in between. For those who really like to tinker with their set-up, this high degree of adaptability should put this shock right at the top of your wish list now.

More information at: extremeshox.com.

About The Reviewer

Johan Hjord - Age: 50 // Years Riding MTB: 18 // Weight: 190-pounds (87-kg) // Height: 6'0" (1.84m)

Johan loves bikes, which strangely doesn’t make him any better at riding them. After many years spent practicing falling off cliffs with his snowboard, he took up mountain biking in 2005. Ever since, he’s mostly been riding bikes with too much suspension travel to cover up his many flaws as a rider. His 200-pound body weight coupled with unique skill for poor line choice and clumsy landings make him an expert on durability - if parts survive Johan, they’re pretty much okay for anybody. Johan rides flat pedals with a riding style that he describes as "none" (when in actuality he rips!). Having found most trail features to be not to his liking, Johan uses much of his spare time building his own. Johan’s other accomplishments include surviving this far and helping keep the Vital Media Machine’s stoke dial firmly on 11.

Photos by Johan Hjord and Nils Hjord