27/12/2023

SPECIALIZED TARMAC SL8 PRO VS SPECIALIZED AETHOS PRO

The Specialized Tarmac SL8 Pro - Ultegra Di2 and Aethos Pro - Shimano Ultegra Di2 are both high-performance road bikes from Specialized, but they cater to slightly different preferences and riding styles.

Tarmac SL8 Pro - Ultegra Di2: This bike is designed with a focus on aerodynamics and speed, making it ideal for competitive riders and those who prioritize performance in racing or fast-paced road riding. It combines advanced aerodynamic design with lightweight construction.

Aethos Pro - Shimano Ultegra Di2: The Aethos Pro is engineered for a perfect balance of lightweight and ride quality. It's an excellent choice for riders who value a more classic road bike feel with modern technology. This bike is more suited for long rides, climbing, and those who prioritize comfort and balanced performance.

Choosing between them would depend on your specific riding needs and preferences. If speed and racing are your main goals, the Tarmac SL8 Pro might be more suitable. If you're looking for a well-rounded, comfortable ride for longer distances, the Aethos Pro would be a better choice.

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1. Price | Weight | Material

SPECIALIZED TARMAC SL8 PRO
SPECIALIZED AETHOS PRO
Price: £
8,000.00
Price: £
8,200.00
Weight:
7.16
Weight:
6.93
Frame Material:
Carbon FACT 10r
Frame Material:
Carbon FACT 10r

2. Frame and Fork

SPECIALIZED TARMAC SL8 PRO
SPECIALIZED AETHOS PRO
Frame:
Sizes 44 49 52 54 56 58 61
Frame:
Sizes 49 52 54 56 58 61
Fork:
FACT 10r Carbon, 12x100mm thru-axle, flat-mount disc
Fork:
FACT Carbon, 12x100mm thru-axle, flat-mount disc

3. Drivetrain

SPECIALIZED TARMAC SL8 PRO
SPECIALIZED AETHOS PRO
Front Derailleur:
Shimano Ultegra Di2 R8150, braze-on
Front Derailleur:
Shimano Ultegra R8150, braze-on
Rear Derailleur:
Shimano Ultegra Di2 R8150, 12-speed
Rear Derailleur:
Shimano Ultegra R8150, 12-speed
Cassette:
Shimano Ultegra, 12-speed, 11-30t
Cassette:
Shimano Ultegra, 12-speed, 11-30t
Crank:
Shimano Ultegra R8100 with 4iiii power meter - 52/36T
Crank:
Shimano Ultegra R81000 - 52/36T

4. Brakes

SPECIALIZED TARMAC SL8 PRO
SPECIALIZED AETHOS PRO
Brakes:
Shimano Ultegra Di2 R8170, hydraulic disc
Brakes:
Shimano Ultegra R8170, hydraulic disc

5. Wheels and Tyres

SPECIALIZED TARMAC SL8 PRO
SPECIALIZED AETHOS PRO
Wheels:
Roval Rapide CL IIRoval Rapide CL II 21iW 51/60mm depth
Wheels:
Roval Alpinist CL 21iW 33mm depth
Tyres:
S-Works Turbo, 2BR, 700x26mm
Tyres:
S-works Turbo 2BR, 700x28mm

6. Cockpit and Seat

SPECIALIZED TARMAC SL8 PRO
SPECIALIZED AETHOS PRO
Handlebars:
Roval Rapide Handlebar, carbon
Handlebars:
S-Works Short & Shallow, 125mm Drop, 75mm Reach w/Di2 Hole
Stem:
Tarmac integrated stem, 6-degree
Stem:
Specialized Pro SL, alloy, 4-bolt
Saddle:
Body Geometry Power Pro, hollow titanium rails
Saddle:
Body Geometry Power Pro, hollow titanium rails
Seatpost:
S-Works Tarmac SL8 Carbon seat post, FACT Carbon, 15mm offset
Seatpost:
Roval Alpinist Carbon Seatpost

7. Conclusion

SPECIALIZED TARMAC SL8 PRO vs SPECIALIZED AETHOS PRO

In the matchup between the Specialized Tarmac SL8 Pro Ultegra Di2 and the Aethos Pro Ultegra Di2, each bike stands out with its unique features and design philosophies. The Aethos, at £8,200, is remarkably lightweight at 6.93kg, while the Tarmac, priced slightly lower at £8,000, weighs in at 7.16kg and includes a 4iiii power meter, a feature not present in the Aethos.

The Tarmac is designed with a focus on aerodynamics, evident in its oversized, aerodynamic head tube and fork shapes, and integrated cable routing through the stem for a clean look. Its aerodynamic prowess is further enhanced by the seat tube and seat post designs. The bottom bracket area of the Tarmac takes inspiration from the Aethos' slimmer design, and it features dropped seat stays for an aero advantage.

On the other hand, the Aethos opts for a more traditional style with its classic front end, slimmer forks, and exposed brake hoses. It maintains a clean appearance thanks to the semi-wireless Ultegra groupset. The round bars, exposed seat clamp, and circular shapes of the seat tube and post hark back to classic road bike designs.

Both bikes share the same seat and almost identical geometries. However, the Tarmac's Horizontal Top Tube Length is slightly longer by 1mm at 563mm for a size 56 frame.

Diving into the wheelset details, the Tarmac is equipped with Roval Rapide CL II wheels. These wheels are tubeless-ready, with a hooked rim design, priced at £1,500, and weigh 1590 grams per set. They feature a 51mm deep front rim and a 60mm deep rear rim, with an internal rim width of 21mm. In contrast, the Aethos comes with the Roval Alpinist CL wheels. Full wheel comparison below.

Both the Specialized Tarmac SL8 Pro and the Aethos Pro are equipped with S-Works Turbo, 2BR tires, but they differ in width. The Tarmac features 26mm wide tires while the Aethos is equipped with slightly wider 28mm tires.

S-Works Turbo, 2BR Tires

  • Type: These tires are known for their high performance, combining speed, grip, and durability. The "2BR" stands for 2Bliss Ready, indicating that these tires are tubeless-ready. This offers the advantage of running lower tire pressures for increased grip and comfort without the risk of pinch flats.
  • Material and Build: They are constructed with a compound that balances rolling resistance and grip, making them suitable for a variety of road conditions.

The 26mm width is slightly narrower, which is typically associated with lower rolling resistance and a focus on speed and efficiency. The 28mm width provides a bit more volume, which can translate to better grip and comfort, especially on rougher roads or longer rides.

In conclusion, choosing between the Aethos and the Tarmac will depend on personal preferences for weight, aerodynamics, and overall style. The Aethos excels in classic aesthetics and lightness, while the Tarmac stands out for its aerodynamic efficiency and integrated technology, offering diverse experiences to passionate road cyclists.

Here's a detailed comparison of the wheelsets for the Specialized Tarmac SL8 Pro - Ultegra Di2 and the Aethos Pro - Shimano Ultegra Di2, incorporating the updated specs:

Wheel comparison:

Roval Rapide CL II (Tarmac SL8 Pro)

  • Type: Tubeless-ready with hooked rim design.
  • Price: £1,500.00.
  • Weight: 1590 grams per set.
  • Rim Depth: 51mm deep front rim and 60mm deep rear rim.
  • Internal Rim Width: 21mm.
  • Characteristics: The Roval Rapide CL II is designed for aerodynamic efficiency, offering a speed advantage on flat courses and stability at high speeds. The deep rims at the front(51mm) and rear(60mm) provide a balance of aerodynamics and handling, making them well-suited for competitive racing and speed-focused riding.

Roval Alpinist CL (Aethos Pro)

  • Type: Clincher, designed for use with tubes only.
  • Price: £1,400.00.
  • Weight: 1365 grams per set.
  • Rim Depth: 33mm.
  • Internal Rim Width: 21mm.
  • Characteristics: The Roval Alpinist CL is focused on lightness and climbing efficiency. The shallower rim depth and lighter overall weight make these wheels ideal for riders who prioritize climbing and agility over flat-out aerodynamics. These wheels are particularly advantageous in hilly terrains and during ascents where weight savings can translate to significant performance gains.

Comparative Analysis

  • Purpose and Terrain Suitability: The Roval Rapide CL II is more aerodynamically inclined, favoring flat, high-speed segments where aerodynamics play a critical role. In contrast, the Roval Alpinist CL is better suited for hillier, more varied terrain, offering superior climbing performance and handling.
  • Ride Quality and Handling: The deeper rims of the Rapide CL II might offer better aerodynamic performance but can be more susceptible to crosswinds. The lighter Alpinist CL provides a more comfortable and responsive ride, especially in windy conditions or steep climbs.

This comparison shows how the wheel choices on each bike align with their overall design philosophies: the Tarmac SL8 Pro focusing on speed and aerodynamics, and the Aethos Pro emphasizing lightness and climbing efficiency.