Specialized Aethos - The Full Scoop

Introduction

Why are you even here? Are you actually in the market for a $7,000 racing bike? Or do you just love bikes and/or albertnet? Wait, don’t leave, I’m gonna tell you exactly why you’re here, or at least why you should stay.

Most bike magazine reviews are, let’s face it, kind of pointless. They’re based on the fleeting impression a journalist (i.e., potentially a non-racer) gets about a bike, filtered through the lens of not offending anybody, particularly a potential advertiser. (See here for the most blatant example of the pay-for-praise faux-journalism model.) The last negative bike review I can remember in “Bicycling” was of the Motobecane Prolight all the way back in 1982, when the reviewer unsparingly and laughingly decried how flex-y it was, only to recant everything an issue or two later, obviously having caught some heat. So much for that. (Full disclosure: I haven’t leafed through a bike magazine in many years so for all I know they’ve completely changed and are now fiercely honest … but somehow I doubt it.)

Of course you might actually be considering buying a Specialized Aethos and have been combing the Internet for reviews etc. like I did. That’s great, and there were some fairly helpful ones, but what I’d wanted to know is what it’s like riding this bike for months, over all kinds of terrain, and the way it was meant to be ridden—that is, jolly hard. I wanted feedback from someone with decades of experience, a real/former racer who could actually put the bike through its paces vs. some columnist I know nothing about. Well, I provide that perspective here, having put over 1,300 miles on my Aethos over flat roads, short but brutally steep climbs, long climbs, dirt roads, and full sprints. And if you’re interested in road bike technology and in industry trends in general, this post gives some color on that, comparing the Aethos to my high-end 2013-era carbon bike with its mechanical shifting and caliper brakes. I’ll weigh in on whether Di2, disc brakes, through-axles, and tubeless tires live up to their promise.

You’ll also get a handy way to compare frame geometry; a comparison of SRAM E-tap vs. Shimano Di2; an analysis of the important differences between the 2025 Aethos and the 2026 Aethos 2; and a primer on how and why to name your bike. If all goes well you might even get a chuckle or two.

Why the Aethos?

I’ve always liked Specialized bikes. My wife and I crossed the country on them in 1994, she on the Rockhopper Comp I sold her the day we first met, me on my Stumpjumper Comp. (We still have them.) Plus, Specialized supports the NICA high school mountain bike racing program for which I’m an assistant coach. On top of that, one of my most esteemed cycling pals, Craig, rides the Aethos and watching him drop me on it, repeatedly, has made an impression (though in fairness he also dropped me on his Canyon, which he threw over for the Aethos). Finally, the bike looked good on paper, which can mean a lot.

When I shop for a road bike, the main thing I look at is frame geometry. I have to believe that any modern carbon fiber frame is going to be light, stiff, etc. and in my experience the main thing that will differ from one make and model to another, and significantly affect the ride, is the design of the frame: seat tube angle, head tube angle, top tube length, and wheelbase. This is, after all, what differentiates a touring bike from a racing bike. As  explained here, I once bought a frame online without knowing the head tube angle, and discovered on that bike’s maiden voyage that it was too slack, a major letdown. Following that misadventure I rode nothing but custom made frames for the next decade. That was in the days of aluminum; I have yet to encounter a company what will build a carbon frame custom. So you have to choose carefully among stock frame geometries.

Since this might be getting a bit dull, I’m going to proceed with this review in the time-honored tradition of The Good, The Bad, and The Ugly. Cue the Ennio Morricone score of this iconic western (and if you want to quibble about my use of the Oxford comma just now, click here and/or email me).

The Good

If I hadn’t committed myself to this good/bad/ugly structure I’d use a stronger word, like amazing. As you can see here, I’ve had a lot of high end racing bikes, and I’m here to tell you the Aethos is the best I’ve ever ridden. It’s the lightest, at 15.8 pounds (in size XL no less); is just as stiff as its last five predecessors (i.e., I can’t flex it); is the most comfortable in how it soaks up the bumps; and feels the most surefooted on descents. The ride is so plush, it’s as though the asphalt were carpeted. And when I stand on the pedals, the bike just leaps to life, like it’s snapping to attention—“Yes, sir!” I’ve never experienced a bike that’s so lively, and I guess it’s down to overall low weight and the crazy light carbon rims. And the geometry chart of the Aethos doesn’t lie: as expected, the handling of this bike is superb. For the last ten years I was on a Giant TCR Advanced, with a 73° head tube angle, and until I rode the Aethos I didn’t even realize how much I missed the 74° that I had on my custom bikes. (Note that all my geometry figures herein are based on my size of frame. Smaller frames will have differences, but the design characteristics are typically consistent across sizes.)

Here’s the thing about a steeper head tube angle: it does make a bike a bit twitchier, but in the best possible way. A bike with a 74° head tube angle will dive happily into a curve, vs. bike with a 73° that kind has to be coaxed. It’s like the difference between Tigger and Eeyore. Yes, more skill and attention is demanded of the rider, but it’s well worth it. I so prefer the steeper head tube, I really can’t understand why any company producing a racing bike would ever choose 73°. But then, companies produce all types of retarded shit, like social media, aerosol whipped cream, microwave popcorn, and soft drinks. It’s a weird world.

My custom bikes had a 72° seat tube angle which I always thought was crucial. The Aethos has a 73°. I find that a) I don’t miss the shallower seat angle as much as I’d expected, and b) this geometry discussion has gone on long enough.

Of course not all of the enjoyment I get out of this bike comes from the featherweight frame and the great geometry. The wheels are also super light, and though they’re probably not as aerodynamic as the Dura-Ace ones I raved about in these pages, they have wider rims, which—coupled with the wider tires and tubeless-ness—give a much nicer ride and presumably lower rolling resistance. Nothing about this bike feels slower on the flats that my Giant, which had aero head  and seat tubes and an aero seatpost in addition to those punishing wheels. Yes, the Specialized Tarmac and other bikes are more aerodynamic than the Aethos, and if you like to haul ass on the flats, of course you should factor that in.

My old bike had Dura-Ace 9-speed with a worn-out right shifter that barely worked. So obviously upgrading to 12-speed Di2 electronic (albeit only Ultegra) wasn’t going to cause any complaint. Not surprisingly, the shifting is excellent. At first I was a bit bothered by the whirring sound of the front derailleur, but actually it does something really clever: it moves just enough to shift the chain, and then a fraction of a second after the shift is complete, it moves again, just a tad, to give the chain more clearance so it’ll never rub. This gets around a compromise traditional derailleurs have always had to make. And I don’t think SRAM does this—I’ve rented three or four top-end bikes with eTAP over the last eight years, and all of them threw the chain at least once (details here). For road bikes, Shimano is better and if you don’t agree you can come fight me. Now: would I say everyone should be on electronic? My answer is still no. Modern cable-pull shifting, when your equipment isn’t twenty years old and totally worn out, is great.

I’d never run tubeless before but now was the time. As detailed here, I see no legitimate reason not to adopt this technology. Oddly, the mechanic who built the bike for me recommended tubes, saying unless you’re going with super fat tires at really low pressure, you run the risk of spewing sealant everywhere when you puncture, especially when the tires are worn. Well, these S-Works tires (which ride great, by the way) are now completely worn out and I never had a problem, other than with a twisted valve as detailed here (and now I’ve got that sorted). Installation was easy. The ride is lovely, reminding me of the plush feel of tubulars (aka sew-ups) back in the day. The slightly wider (28C) tubeless tires are surely part of why this bike is so comfortable.

Do through-axles make a difference? Well, it’s hard to say, because nobody just goes from old-school quick-release hubs to through-axles without changing pretty much everything else. This technology means carrying an Allen key, but that’s no biggie. (I almost said “Allen wrench” but that sounds too heavy.) But I will say, this through-axle setup must exist for a reason (better stiffness and better disk brake alignment, I suppose) and like I said before, this bike descends beautifully and maybe this is part of the equation.

Speaking of disc brakes, are they a game-changer? Well, I certain can’t complain. The rotors tend to stay cleaner than rims which is mainly a benefit on mountain bikes but does simplify maintenance on this bike, too. Hydraulic brakes are a bit more powerful than the Dura-Ace caliper brakes on my old bike, and if I ever get caught riding in the rain I’ll really appreciate them. I also don’t miss the hiss of my old brakes (particularly when the rims were grimy) but then, I dread the day my hydraulic brakes start moaning for no reason.

It’s a real treat to buy a bike and not feel like you have to replace anything. My Aethos is completely stock, down to the bar tape and the saddle, and even those are great. The saddle is super light carbon fiber and—once I got used to it, which took just a ride or two—is totally comfortable. For a while it started creaking, especially on really steep climbs, but before I got around to troubleshooting the problem, it went away.

The Bad

Okay, I lied about not having to replace anything. The stem this bike came with, though perfectly fine (I mean, it’s a piece of metal…), was too short. I’ve never seen an XL bike before that came equipped with an 11 cm stem. For this much money, the company ought to let you swap it out for free, but this is not the case. Weirder still, I couldn’t find a Specialized stem in matte black to match the bars and the overall matte finish of the bike, and I looked everywhere. I finally had to source a Ritchey stem, for like $130. That kind of stung after all the money I’d already shelled out. And imagine if I’d gone with the Tarmac SL8 Pro, with its integrated cockpit … that’d be over $500 and a royal pain in the ass to change out.

Another minor issue is that I have to remember to charge the battery on this bike. I first realized this about half an hour into a five-hour ride with my pals, after I’d had the bike about a month. (Fortunately the battery did hold out.) Charging my bike is just another ongoing task to keep track of, and there’s so much tech in my life already. I know I could get the Di2 app for my smartphone and thus have an easy way to check the battery, and even to adjust the shifting (I think someone said), but reviews of the app are generally fairly weak, and a few of the 1-star reviews complained that a firmware update that went wrong bricked the entire bike, requiring a trip to the shop to get sorted out. Life is too short to delve into such things, at least for now. With my old bike, I never need an app or a charger, and I can fine-tune the indexing while riding.

I guess the only other thing I could complain about is how expensive this bike was (and of course that’s not a complaint about the Aethos per se, it’s the entire industry). Which reminds me: if you’re thinking of breaking into my house to steal this bike, think again! Since I work from home, the only time I’m not here is when I’m out riding, so the bike will be gone too, duh! Plus, as far as you know I have a pit bull whom I’ve trained to rip the zipper out of a pair of jeans, and/or a resident weird uncle who is a gun nut and fantasizes constantly about defending my home and property.

The Ugly

You can decide for yourself based on the photos above whether anything is ugly about this bike. Myself, I think it’s cool looking. I like the color, and the lines, and the very subtle branding. On the downside, I don’t care for the spacers I’ve kept, for now, in the steerer tube stack, two of them above the stem. At some point I’ll probably cut down the steerer, if I decide I’m confident enough in my ageing back to commit to the current stem height. But that’s a minor point. You know what is ugly, though? The modern aero stems like what come on the Tarmac and on the Aethos 2 Pro. Look at these.

It’s like they’re embarrassed about being mechanical. (I’m reminded of the little knit covers, sometimes with a pompon on top, that some people put over their spare roll of toilet paper, as if ashamed of it.) All that plastic … it’s like the modern car industry, so much window dressing. And consider that in the catalog photos the steerer is cut all the way down … with the stem up a bit, you have to use weird non-cylindrical washers, and the assembly starts to look more and more janky, especially if there are spacers above the plastic cowling as well. Look, a bicycle is a tool, and it’s mechanical, and it’s okay—even desirable—to show that. Stop trying to make everything into a Rivian or an iPhone! Meanwhile, I’m not bothered at all by the looks and supposed wind drag of the exposed hydraulic lines. (Aesthetics aside, bleeding disc brakes is enough of a hassle without internal routing.)

I also don’t like the small rear triangles of so many modern road bikes, including the Tarmac. They look kind of stunted to me. This setup is supposedly stiffer and maybe even more aero than the traditional setup, but I don’t need extra stiffness, and this bike is aero enough, and even Specialized concedes that the Aethos has a more comfortable ride than the Tarmac, which I’m guessing is due to the larger rear triangle. But mainly I just like the look of these stays.

One of my original complaints with electronic shifting is that it makes the derailleurs large and more bulbous. They’ve gotten a lot better, but I still don’t love the look of them.

But then, who looks closely at this stuff anymore? As a teenager I scrutinized every part at length, but now my eyes aren’t even that good and I can’t be bothered to squint. It’s all a blur, it’s all good.

Naming the bike

A bike should mean more to its owner than, say, a microwave oven or dresser does. Because of the way a great bike disappears beneath you, it kind of feels like an extension of yourself. Suffering for hours at a time on your bike kind of bonds you to it as well, like you’re sharing this bold adventure; I wonder if this is how cowboys think of their horses. Thus I name my bikes, as should everyone. My Giant is called Sirius Black (named when my kids were still reading Harry Potter); my 3-speed is the Arseless (short for Arseless Horse, which name I stole from the writer Roddy Doyle); my mountain bike is NOS (for “new old stock” because it had been forgotten in a warehouse for a couple years before I bought it, and as a nod to the rapper Nas).

I thought of my Aethos’s name when I was showing it to my younger daughter. She asked what I liked best about it and I described how the steering is quicker than on other bikes. She asked why all bikes aren’t made like this and I said it’s a bit trickier to handle, like Porco Rosso’s seaplane. And suddenly it dawned on me how good a name Porco Rosso is for this bike. I mean, it’s red; it’s kind of the color of rare pork; it has that quick handling like the plane; and we all love Studio Ghibli. Both my kids agreed with me immediately: not only could I name this bike Porco Rosso, but I had to. Done.

The Aethos 2

It’s probably in adherence to a corollary of Murphy’s Law that as soon as I decided to review this bike, a new version came out threatening to render everything you’ve just read obsolete. But actually, hold on: there are important differences between mine and the new version, and if I were buying a bike today I’d still go with the original Aethos. With new model, they basically wrecked the geometry. Click here for a really cool website that makes it easy to compare geometries, and shows how the Aethos 2 differs. It’s got a shorter top tube, a shallower head tube (!), a steeper seat tube (!!), and a longer wheelbase. It’s basically a touring bike, designed for people who want to sit up straight and tall like the wicked witchy neighbor woman in The Wizard of Oz. The good news is, even if you’re reading this review too late to snap up an original Aethos, the Tarmac geometry hasn’t changed (i.e., it’s still effectively the same as my Aethos). You’ll just have to settle for a very slightly heavier bike that is harder to service and isn’t so pretty (though it’s more aerodynamic).

Are there other changes in the Aethos 2? Yes, it will take 35 mm tires if you really want to gild the lily (i.e., if you’re basically looking for a 15-pound beach cruiser). And as the Specialized website proudly proclaims, “no gram was safe from our scalpel”—they shaved 9 grams with the new seatpost, 6 grams with the new bottom bracket shell, 2 grams with the new brake mounts, and 2 more with the new derailleur hanger. Seriously, guys? Grams? These are trivial savings. Why not just wipe off some of the road grime, or blow your nose before your ride?

Conclusion

If your road bike is more than a few years old, and you like to climb a lot, and you’re a seasoned rider who isn’t afraid of a fast-handling bike, what are you waiting for? DO IT DO IT DO IT DO IT.

Postscript

In case you were wondering, Specialized did not compensate me in any way for this positive review, and I would be required to disclose this if they had. I truly am just an honest, happy customer.

Related reading

• From the Archives - The CarbonTech Debate
• Test Ride - Specialized Turbo Levo SL 2 Carbon E-Bike
• What’s Wrong With Shimano?
• Letter to a Middle-Aged Cyclist - Buy New Wheels NOW!
• Bomb Pop - A Bicycle Retrospective
• A Cheap Bastard’s Guide to Inflating Tubeless Tires
• Colorado Mountain Road Test - SRAM eTap Electronic Shifting
• Disc Brakes for Road Bikes?
• Carbon vs. Steel & the Bike Geek Divide

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