Specialized Aethos Comp review: More affordable, more weight, still magical

Even an extra 100 g and heavy parts can’t dull this frame's luster.

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Story Highlights

  • What it is:The spirit of Specialized’s S-Works Aethos, but with a slightly toned-down frameset and a lower-cost build kit.
  • Frame features:Ultralight carbon fiber construction, traditional tube profiles and shaping, conventional cable routing and frame fittings, clearance for 32 mm tires.
  • Weight: 699 g (claimed, 56 cm frame only); 7.78 kg (17.16 lb), 52 cm size, without pedals.
  • Price: US$5,000 / AU$6,900 / £4,500 / €5,400
  • Highs:Superb chassis efficiency and handling, excellent ride quality, generous tire clearance, classically understated aesthetics, headache-free cable routing, proprietary (almost) nothing, SRAM Rival AXS works just as well as Red and Force.
  • Lows:Heavier than some might like, mediocre (and poorly built) wheelset, almost impossible to get.

I reviewed the top-end Specialized S-Works Aethos back in October and found it to be a truly exceptional road bike. It’s incredibly light, it rides very well, it handles great, and generally just feels oh-so-good in a way that’s increasingly lacking in modern road racers that place a higher priority on numerical gains. It’s one of a small number of test bikes I’ve missed since the day I handed it back.

Then again, the bike I tested retails for a whopping US$12,500 / AU$18,500 / £10,750 / €11,800, so in reality, anything less than an emphatically impressive ride experience could be considered an abject failure. 

Alternatively, the Aethos Comp Rival eTap AXS model offers a nearly identical frame with a lesser build kit for less than half the price of the S-Works model. Is the Aethos frame so inherently good that it can withstand an extra 1.7 kg (3.75 lb) in ballast without changing its personality, or is it a case of the parts having an outsized influence on the whole? 

Luckily for Specialized, my experience has shown it to be the former. This more affordable version may be heavier than the flagship model, but it’s still an amazing bike to ride, and I’ll miss this one when it’s gone, too.

A hundred grams of nothing

Looking at it in terms of percentages, the standard version of the Aethos is nearly 20% heavier than the S-Works version. That sounds like a lot on paper until you consider the claimed weight for a 56 cm painted frame is still just 699 g (as compared to the 585 g for the S-Works version), and the fork is identical at just over 300 g with an uncut steerer tube.

In other words, it’s heavier, but it’s far from heavy.

Given how seemingly every high-end road bike these days has adopted truncated airfoil tube profiles, these round ones are a refreshing throwback.

According to Specialized, the only critical difference between the two frames is the grade of carbon fiber used. Aside from the addition of a cable entry port on the top of the down tube and threaded fittings for housing stops and cable guides (which make the second-tier Aethos compatible with mechanical drivetrains, unlike the S-Works version), there are no visual differences whatsoever. Additionally, Specialized contends there’s no difference in terms of stiffness or ride quality, either.

“That weight added on the frame and fork is basically a result of substituting some lower-cost material in the mix,” explained Stewart Thompson, Specialized’s road and gravel category leader. “Some of the complex layup plies and overlaps are simplified as well. With these changes, though, we’ve maintained the same stiffness and ride quality between the 10r and S-Works platforms so the only tangible difference between the two is weight.”

The two frames may only differ in weight by about 100 g, but the difference in cost is far, far more dramatic. 

Retail price for the S-Works Aethos frameset is a whopping US$6,000 / AU$8,500 / £4,500 / €5,000, but the price tag for the second-tier version is a lot less jarring at US$3,300 / AU$5,500 / €3,600 (sorry, Brits, no soup for you). Comparatively speaking, that makes the standard Aethos one heck of a bargain.

Nope, no dropped seatstays to be found here, folks.

Even better from a value point of view is the “entry-level” Aethos Comp complete bike, which comes equipped with SRAM’s new Rival eTap AXS wireless electronic groupset, a nice carbon fiber seatpost, a decent aluminum bar-and-stem setup, and DT R470 rims on generic cartridge bearings hubs for US$5,000 / AU$6,900 / £4,500 / €5,400. Depending on where you live, that means you can buy a complete Aethos bike for less than the cost of the S-Works frameset.

Not surprisingly, the Aethos Comp isn’t quite as jaw-droppingly light as the S-Works version. Rival eTap AXS is heavier than Shimano’s 105 mechanical groupset, and the DT Swiss R470 wheels aren’t exactly featherweights, either. But like with the frame, the complete Aethos Comp may be nowhere near the stellar 6.10 kg (13.45 lb) weight of the flagship S-Works Aethos when equipped with Shimano Dura-Ace Di2, but it’s still hardly heavy at 7.78 kg (17.16 lb) in my 52 cm size (without pedals or accessories). 

Still so, so good

There are lots of factors that contribute to how a bike performs out on the road: stiffness, weight, frame geometry, aerodynamics, vibration damping, and so on. Heck, color even matters (really). However, even the best engineers in the industry still struggle to translate into reliable test bench numbers exactly what makes a bike feel good to its rider.

Whatever “it” is, even this somewhat watered-down version of the Aethos still has it.

One thing that’s certain is that weight isn’t everything — never has been, and never will be. And in the case of the Aethos Comp, that additional 2 kg of ballast might be noticeable, but it somehow doesn’t detract from the S-Works Aethos’s magnetic personality.

The chainstays are curiously slender, but the back is nevertheless solid under power.

Just as on the S-Works version, the Aethos Comp is incredibly reactive and responsive when you apply the power. Like most good race bikes, it’s eager and tightly wound in the way it wants to surge forward as you push on the pedals. It wants to go faster, but it’s also perfectly content to cruise along and is just as enjoyable when doing so, too. As with seemingly every road bike I’ve loved over the years, there’s also this wonderful flex pattern to the whole thing that lends this weird sense of liveliness and synergy.

Likewise, the handling is brilliant — as you’d expect since it’s derived from the similarly superb Tarmac. Changing directions requires just the slightest lean or flick of your wrists, and you practically just have to think about changing your line mid-corner to make it happen. Yet as agile as it is, it’s still confidently stable when you’re in a full tuck and going way faster on a descent than you should. You don’t have to relearn anything to get the most out of this thing; you just do everything as you’ve always done it, and the Aethos somehow makes the experience better.

As for the other part of the geometry equation, the riding position is rather aggressively long and low, but far from extreme. That said, as I said in my review of the S-Work version, if Specialized really does intend for the Aethos to be primarily used for something other than racing, I still think the company missed an opportunity to split the difference between the Tarmac and Roubaix in terms of riding position. 

There are no misgivings in my opinion in terms of the ride quality, which feels identical to that of the S-Works version. It’s not particularly cushy, but at least for this 71 kg rider and in my 52 cm test bike size, it straddles the line between uncomfortably firm and mind-numbingly muted with a communicative personality that lets you know what’s going on at the contact patch without yelling in your ear. And if you really want more comfort and/or capability, there’s room at both ends for 32 mm-wide tires, which makes the Aethos Comp quite the machine for smoother dirt roads and poor-quality tarmac. Some bigger tires will fit, too, but that’ll depend on the exact make and model of tires and rims you use, along with your risk tolerance for rub.

Maxing out the tire clearance makes for a remarkably capable ride on bad pavement or smoother dirt roads.

The icing on the cake comes in the form of the same English threaded bottom bracket shell that Specialized uses on the S-Works model, the same external aluminum seatpost collar and 27.2 mm-diameter round seatpost, and the same elegantly understated paint that is so refreshingly devoid of in-your-face logos. 

This all sounds too good to be true, right? Especially from a bike that costs barely one-third the flagship version? Well, maybe so, but based on the comments I’ve received from CyclingTips readers who have since purchased various Aethos models of their own, either we’re all drinking the Kool-Aid or there really is something special here.

Spec notes

I’ve already written at length about the Aethos Comp’s SRAM Rival eTap AXS wireless electronic groupset. Nope, it’s not light — far from it, in fact. But in terms of how it works, it’s virtually a carbon copy of the top-shelf Red eTap AXS version, with identically reliable shifts, similar power and control from the hydraulic disc brakes, and lever ergonomics that are arguably even better than what SRAM offers higher up in the food chain. Granted, the levers’ more compact shape comes as the expense of optional remote shifter buttons and adjustable brake lever throw, but I never use the latter, anyway, and SRAM may have a solution for the former, too. 

In short, it’s excellent stuff.

Rival AXS may be the entry-level offering in SRAM’s wireless electronic road groupset range, but I’d argue these levers feel better than the Force or Red ones.

Kudos to Specialized’s product managers and component division for the excellent finishing kit, too. 

The Body Geometry Power Sport saddle’s hollow Chromoly steel rails may weigh more than titanium or carbon fiber ones, but the shape is the same as on higher-end Power models that are so widely lauded, and it’s mounted to the same ultralight carbon fiber seatpost that Specialized uses on the S-Works Aethos.

Meanwhile, the semi-anatomic bend on the aluminum bar is one of my favorites, and although the forged aluminum stem isn’t anything special, it doesn’t need to be, either. It’s admirably lightweight and holds securely, and its svelte shape meshes well with the rest of the Aethos frameset. Topping things off is grippy and nicely cushioned handlebar tape from Supacaz (a company started by the son of Specialized founder Mike Sinyard). 

The aluminum cockpit may not be as fancy as a carbon fiber one, but there’s also less concern in the event of a minor wreck, too.

Surely there’s a bigger catch somewhere, right? 

Well, yes, actually, there is. This isn’t some mythical fairytale land, after all.

The wheels on the Aethos Comp are decidedly ho-hum, made up of DT Swiss R470 aluminum rims, DT Swiss stainless steel spokes, and sealed bearing hubs for a grand total of just under 1,800 g. The R470 rim is appropriately wide at 20 mm between the bead hooks, they’re tubeless-compatible (and pre-taped), and they’re decently light with a claimed weight of 450 g apiece. However, they’re made with a pinned seam instead of a welded one, and I personally don’t like the long-term prospects of aluminum rims that aren’t fitted with eyelets. 

The DT Swiss R470 rims seem fine on paper, but the wheelset, on the whole, is a little disappointing.

As for the spokes, I appreciate that they’re from a major brand, but the 14 g straight dimensions add weight (and drag, if you’re concerned about that sort of thing). That said, the matching DT Swiss brass nipples are nice to see if you’re worried about corrosion.

A bigger downer is the hubset. They’re painfully generic (though, upon closer inspection, supplied by OEM brand Formula), with no-name cartridge bearings and a notably slow engagement on the pawl-type aluminum freehub body. My test set spun smoothly, but any maintenance issues down the road could be problematic in terms of things like sourcing a replacement freehub body or other small parts.

The most disappointing aspect was the build quality. The wheels came out of the box considerably out of true, and the spoke tension wasn’t as even as I would prefer, either; both should be corrected by a qualified mechanic before riding. Specialized at least wraps these with its excellent Turbo Pro clincher tires, although I would have liked to see the 28 mm size fitted instead of the less-forgiving 26 mm ones.

The hubs spins just fine, but finding replacement parts could be a problem long-term.

Looking at the bright side, upgrade-minded buyers will see the mediocre wheels as a prime target for replacement — and I can say after doing such a swap myself that much of the perceived performance gap between the Aethos Comp and higher-end versions can be closed with a switch to even a mid-range carbon wheelset with nicer tires. With prices on those wheelsets plummeting in recent years, even that significant of a cost addition still makes for an appealing performance bargain that I’d strongly consider myself were I in the market for something like this.

I ended up spending much of the test period with a more reasonably priced upgrade of Specialized Turbo Cotton clinchers and latex inner tubes, and between you and me, would probably just stop there if I were keenly focused on my bottom line.

The whole is more than just the sum of its parts

When I got into riding, the prevailing rule when looking at a complete bike was to buy the best frame you could afford now, and then upgrade the parts later as your needs (and budget) allowed. Without question, you can find a road bike with a nicer build kit than what this Aethos Comp offers (particularly if you’re able to find a high-end aluminum frame with rim brakes) and is arguably a more well-rounded machine. 

I’m still hopeful the Aethos will prompt other major brands to stop chasing numerical performance gains in favor of more visceral improvements.

Cannondale’s Shimano 105-equipped CAAD13 comes to mind, for example. That bike costs less than 40% of this Aethos Comp, yet it’s still half a kilo heavier despite using a mechanical drivetrain and rim brakes. In fairness, a CAAD13 with Ultegra mechanical and lower-end carbon wheels would be a fairer comparison price-wise, but even then, it wouldn’t feel as good as this thing does.

Simply put, the Aethos is one of the finest-riding road frames I’ve ever experienced, and the fact you can buy a complete example with as much technology and functionality as you can here at such a relatively attainable price makes this an easy choice in my head. To hell with the extra weight. This one gets two big thumbs up from me — but good luck finding one.

More information can be found at www.specialized.com