Specialized has revamped the Aethos for the greater good… but after a test ride, I’ve decided I won’t be upgrading (yet)

Five years on from the launch of the Aethos, Specialized has revealed the Aethos 2, a more relaxed road bike with the focus still very much on low weight, handling and simplicity. However, in making the geometry taller and revising the layup for more comfort, Specialized has made the Aethos a fraction heavier and taken it in the direction of an endurance bike.

Armed with several years of gen 1 Aethos ownership, I went to Dorking to test the new bike.

New frame tech

As the Aethos places a fair amount of emphasis on weight, it might surprise you to learn that the frameset is heavier than the original. The additional 10g takes a painted 56cm S-Works frame, without hardware, to 595g.

Should you want the Pro frame as I tested in the Surrey hills, your frame will weigh 705g.

A 56cm, painted S-Works AXS model weighs a claimed 5.98kg, while the Aethos Pro AXS is a claimed 6.71kg. 

Along with some additional surface area due to the higher ride position and longer wheelbase, Specialized says that a layup change and minor alterations to the tube shapes have resulted in a more comfortable ride.

While the frame overall is heavier, Specialized was keen to stress that savings have been made around the frame. A new saddle clamp saves a claimed 9g.

The bottom bracket has apparently been trimmed by 9g, 2g has been shaved off the front brake mount and a further 2g will be saved through Specialized’s own UDH (Universal Derailleur Hanger) design.

But the most interesting of the weight savings comes with the bike’s overall weight. The new Alpinist CLX III wheels, launched late last month, come with thermoplastic spokes, Ti ends, an ETRTO compliant design, a 21mm hooked internal rim width and a feathery 1,131g claimed weight. This, for clarity, includes valves and tape.

Onto these wheels you’ll now be able to fit 35mm tyres with 4mm of clearance on either size. Specialized is generally rather conservative with its tyre clearance claims, so wider tyres may be possible.

At the front you’ll find that Specialized has hidden the brake hoses internally, routing them through a larger upper headset bearing. To go with this, a new Alpinist cockpit has been designed with a deeper top section and a much improved size range.

But with this new design comes compatibility. Specialized sticks with a 1 ⅛” steerer tube, meaning a wide range of stems and cockpits, including its own Rapide aero cockpit, can be fitted.

Sensible choices

The Aethos appealed to many riders, including myself, for its simplicity and understated design. Fans of the gen 1 bike will be pleased to see that the round tubes remain, though the layup and tube shapes have been tweaked for additional comfort. 

A round 27.2mm seatpost remains at the rear and bonded inserts in the BB shell allow for threaded bottom brackets to be installed easily. I remember there being some questions around the longevity of those bonded inserts when the gen 1 Aethos launched, but I am yet to find any sign of issues on my own bike.

Another sensible change is the introduction of UDH compatibility. Specialized has designed its own hanger, saying that SRAM’s attempt is heavy and ugly. But while this proprietary hanger sounds like the opposite of UDH’s appeal, Specialized says that the standard SRAM hanger will fit just fine. So, if you’re on a ride and your hanger breaks, a replacement should be easy to find.

Geometry and handling

The biggest departure from the original Aethos comes when you look at the geometry figures. The new bike is significantly taller, slightly slacker and gains tyre clearance through a longer wheelbase and lowered bottom bracket.

The slight slackening of the headtube angle by 0.5º, 15mm additional stack across most sizes and 7mm longer wheelbase combine to give a bike that is predictable at speed, if a little tamer in the corners. 

The Surrey lanes of the test ride treated me to a few fun bends, but while the bike felt good, I found myself wishing for the old bike.

I also, despite a bar that was slammed, felt as though I was sitting very high at the front end. This isn’t necessarily a bad thing as being comfortable will likely allow you to hold your best aero riding position for longer. But for those of us that like to really get low, the position may be too tall.

A noticeable benefit of Specialized’s tinkering with the frame design comes on fast descents. The Aethos 2 tracks smoothly with an assuredness that makes flying down an unfamiliar road through dappled sunlight a little less scary. 

Specialized says that it made the changes in response to its fit data, so while these changes don’t suit a rider like me, they will likely make the Aethos more appropriate for the majority. I can’t be mad about that.

Build

During this first ride, I had the Aethos Pro AXS, a £7,249 bike with Sram’s excellent Force groupset. While I have had a little time on SRAM’s latest RED groupset, this was my first experience with the slightly more affordable Force components and I wasn’t left disappointed.

A mid-ride adjustment to the brake reach was all that was needed to leave me feeling perfectly comfortable with the groupset. I would go as far as saying that I prefer the brakes here to the Ultegra 12-speed on my bike at home.

Unfortunately, the Pro builds do not come with the fancy Alpinist CLX II wheels and their thermoplastic spokes, so I can’t comment on how these perform. When wheel brands use carbon spokes to add stiffness and decrease wight, it often results on a wheel that is harsh to ride.

This is fine for racing, where performance matters most, but it can be a little too much when you venture away from good tarmac. We have asked for the new wheels, so a full review shouldn’t be far away.

The Alpinist CL wheels fitted were solid performers, feeling positive when I put down some mediocre power on Box Hill and the Specialized Turbo TLR tyres felt assured through dry corners and under braking.

However, the wheel’s 21mm internal width and 28mm tyres isn’t a combination that I’d be rushing out to buy. Over broken surfaces I found more road buzz coming through to my backside and hands than on my Aethos at home.

The key difference is that my own bike is set up with 30mm Pirelli P-Zero Race TLR RS tyres on Enve SES 4.5 wheels with their 25mm internal rim width. I can’t tell you which setup is faster, but the wider tyres on wider rims provides a comfier ride.

I will be very interested to get the new S-Works frame and Alpinist wheels in for a back to back test with my bike and the original Alpinist hoops to see if there is a tangible comfort difference.

What the Pro build does get, however, is the new Alpinist cockpit which has been slightly redesigned. The tops have been flattened a little for a more oval profile and this works well to create a comfortable and secure grip.

When on the hoods and in the drops, I found the cockpit provided plenty of stiffness. There were also no annoying rattles from poorly routed brake hoses.

But the biggest kudos must go to Specialized for admitting a mistake. With their previous integrated cockpits, the size range available to consumers has been very limited. With this new design, 13 sizes will be available. 

Conclusion

The changes that Specialized has made to the Aethos make the gen 2 more suitable for a wider range of people. The front-end integration looks very slick and seems to have been executed well.

The new cockpit is a lovely piece of kit and I’m delighted to see a proper range of sizes.

While the weight increase to the frame seems disappointing, the changes this has come with make it more than acceptable. 

I’ll be very keen to review the Alpinist CLX III wheels to see how they perform in isolation, but also within the new system.

The Aethos Pro is still an excellent bike, and while the geometry is a bit too tall for me, its weight, ride quality and clean lines make it a great pick for anyone not fussed by aero.