Test Specialized Aethos: Not quite five years after its first launch, the lightweight bike is perhaps even more unique in its departure from the "Aero Road" trend. However, the significantly expanded model range at the lower end makes it accessible to a wider range of customers. It's high time to take another look at the classically styled racing bike!
It's no longer a new trend - but one that pretty much all manufacturers have now adopted: racing bikes are now called "Aero Road" with streamlined tube shapes, grooved seat tubes, tear-off edges, low-set rear stays and flat fork legs. Many racing machines with these features look quite similar; of course, one could argue that the classic steel frames also offered little variety in terms of style. Road bikes that don't fit the aero scheme have become rare, especially in the upper price ranges.
Specialized Aethos: No-frills lightweight racer
However, the fixation on aerodynamic performance at 45 km/h (the typical speed range in aero tests) ignores the reality of life for most racing cyclists. If you average 25 km/h and ride a lot with the top handlebars, you don't even need deep rims. And when riding in a group, it becomes clear that it is fitness rather than the material that makes you faster. Last but not least, a flat racer with a professional look could raise expectations that its shape cannot fulfill - and it makes sense to look for a bike that is a little more discreet and focuses on properties other than air resistance.
Specialized did this with the Aethos almost five years ago. Even then, the bike with its slim round tubes had a slightly "retro" feel; the focus on maximum lightweight construction with a frame that weighed less than 600 grams, making it the lightest in the world, caused quite a stir. The two complete bikes that were available at the time were both in the five-figure range - so for most people, they were just a dream come true.
Significantly expanded model range
However, that has changed in the meantime. The range has been gradually expanded, and today the cheapest version costs just 3.400 euros. In addition to the high-end model of the "S-Works" series made of super-light "FACT 12r" carbon, there are variants with a "FACT 10r" frame, which means a frame weight of around 700 instead of 600 grams - just 100 grams less, which makes up to 2.200 euros in the frame price. The "FACT 2024r" model introduced in 9, which is used in the cheapest Aethos, the "Sport", is even slightly heavier. Its frame weighs only 56 grams in size 850 with derailleur base, derailleur hanger, etc., and the fork a good 300 grams, which is still extremely low.
But that's not the main thing. Much more important is that the Aethos is a slim, no-frills racing machine where the focus is simply on the riding experience, rather than on maximum performance with the least possible effort. The prefix "racing" should therefore be deleted, because Specialized is not targeting racing cyclists with this bike. Instead, it offers all those who want to enjoy cycling in its purest form, rather than chasing seconds, the essence of the racing bike, so to speak.
The Aethos doesn't promise anything that its rider can't keep. The weight, comfort and driving dynamics are impressive in the first few kilometers; now you don't have to wait until you're in peak form to be able to exploit its performance to the full. This bike is fun even at moderate speeds - and that makes things pretty relaxed.
As it has gotten older, the Aethos has only sharpened its profile, as there are fewer and fewer comparable bikes, especially from the major manufacturers. Brake lines routed externally on the cockpit have become rare, even in the cheaper price ranges; the clamp has been replaced by an integrated seat clamp in most cases. On the Specialized, both ensure the sleek look, which includes rear stays that are clearly separated from the seat tube and the slim, round stem. This looks more elegant than the bulky stems of many bikes with integrated lines. Working on the cockpit is of course easier with external brake lines; the same applies to the bottom bracket thanks to the screwed BSA bottom bracket. Both features are interesting when building the frame sets that Specialized offers yourself. Interestingly, the BSA bottom bracket is also becoming popular again with other manufacturers, especially since it is much easier to maintain and install than pressed-in bottom brackets.
High driving comfort without unpleasant flex
With the graceful design, the manufacturer not only aimed for low weight; the Aethos also has a lot to offer in terms of riding comfort - and without any flex zones or extravagances like the Zertz inserts of older Specialized models. The slim fork and the super-light seat post (just under 160 grams) are of course particularly noticeable when it comes to shocks and vibrations, although the post doesn't wobble at all. The frame itself also seems very comfortable without being soft: the brake disc doesn't drag on the saddle when you're out of the saddle, nor does the fork vibrate when you brake. And even at high speeds, the Aethos is pleasantly stable and safe.
Of course there are stiffer frames, but the Specialized is not designed for sprinters. But the fact that it is not a "racing bike" should not be misunderstood: The frame geometry corresponds 1:1 to that of the Specialized Tarmac SL8 and is tailored to a more stretched-out sitting position with low handlebars. And this is another special feature of the Aethos: It is not an endurance bike with a long head tube and, ideally, threaded eyelets for mudguards or accessories. The sitting position is aggressive (especially since you can remove all the spacers under the stem due to the lack of integrated cables), and the handling with the rather short standard stem is almost too playful. And whenever you pick up the pace, get out of the saddle or push the bike into a corner, you can feel the low weight of the slim Specialized: With the new SRAM Red AXS and the very light Zipp wheelset, the "S-Works" top model, including pedals, bottle holders and Wahoo mount, still weighs less than 6,8 kilos.
Fantastically light top model
That's a feat for a 14.000 euro bike, you might say - but that's where the cheaper versions that are now available come into play. All versions, right down to the entry-level model, the Aethos Sport with mechanical Shimano 105, come with the same fork and the same carbon seat post; components such as the extremely light thru axles and the carbon spacers are also used on all models. And since the riding experience, especially in terms of comfort, depends heavily on the fork and seat post, the inexpensive Aethos Sport feels like the most expensive in direct comparison - apart from the extra weight and the components.
A version like the Aethos Expert with SRAM Rival AXS, power meter and carbon wheelset is barely more expensive than similarly equipped competitor products at 6.000 euros, but is significantly lighter than similarly priced bikes. The entry-level models "Sport" and "Comp" can meanwhile be tuned with light wheel sets in terms of weight and handling. Specialized also offers frame sets starting at 3.300 euros. The only thing missing now is an Aethos with an aluminum frame - the model would be the Specialized Crux DSW, the aluminum version of the super-light Crux gravel bike.
Oh yes, the Aethos has of course already proven itself in racing: in 2021, sprinter Kasper Asgreen competed in the first mountain stage of the Tour de France on the lightweight bike instead of the usual Tarmac SL. Sure, it was a marketing campaign - but since then it can no longer be said that Specialized is only targeting hobby riders with its old-school bike.