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The Specialized Aethos Pro Ultegra Di2 Road Bike was created to free the rider, delivering a pure and timeless riding experience where effort disappears and rider and machine move as one.
The Aethos 2 refines geometry, increases tyre clearance, and introduces new Roval components while retaining the sublime ride feel that defined the original. Every improvement was made to extend the experience to more riders without compromise. Drawing on decades of Body Geometry data, the Aethos 2 offers a fit that suits more riders than ever. A taller stack, longer wheelbase, slacker head tube, and lower bottom bracket combine for stable handling, greater comfort, and improved control.
Born from the discovery of how frames flex under load, Flow State Design optimises tube shapes rather than adding stiffness layers. The result is a lighter frame with improved ride quality, greater structural integrity, and unmatched durability.
The Aethos 2 clears 35 mm tyres with ease, adding versatility and comfort without increasing weight. Achieving this required an entirely new carbon layup, perfected through countless refinements for the most elegant ride yet.
The updated Alpinist cockpit and wheels complement the Aethos perfectly. At just 270 g, the Alpinist Cockpit II is more ergonomic, comfortable, and responsive, while the Alpinist CLX III wheels are lighter, stronger, and more durable.
Despite its feathery weight of 705 g, the frame endures testing far beyond industry standards, withstanding over 100,000 pedal strokes at 2,377 watts without issue. Lightness meets strength in perfect balance.
| Size | 49 | 52 | 54 | 56 | 58 | 61 |
|---|---|---|---|---|---|---|
| Stack (MM) | 522 | 538 | 559 | 580 | 606 | 627 |
| Reach (MM) | 373 | 377 | 384 | 391 | 398 | 404 |
| Head Tube Length (MM) | 114 | 128 | 150 | 169 | 198 | 218 |
| Head Tube Angle | 71.4° | 72.1° | 72.5° | 73° | 73° | 73.5° |
| BB Height (MM) | 266 | 266 | 267 | 267 | 269 | 269 |
| BB Drop (MM) | 75.5 | 76.5 | 75 | 75 | 73.5 | 73.5 |
| Trail (MM) | 62 | 58 | 55 | 55 | 55 | 52 |
| Fork Length (MM) | 372 | 372 | 372 | 372 | 372 | 372 |
| Fork Offset (MM) | 50 | 50 | 50 | 47 | 47 | 47 |
| Front Centre (MM) | 581 | 584 | 594 | 599 | 614 | 621 |
| Chainstay Length (MM) | 410 | 410 | 410 | 410 | 410 | 410 |
| Wheelbase (MM) | 978 | 981 | 992 | 998 | 1013 | 1020 |
| Toptube Horizontal Length (MM) | 508 | 526 | 544 | 557 | 572 | 584 |
| Standover Height (MM) | 719 | 737 | 759 | 779 | 805 | 834 |
| Seat Tube Length (MM) | 450 | 470 | 490 | 510 | 535 | 570 |
| Seat Tube Angle | 75.5° | 74.5° | 74° | 74° | 74° | 74° |
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Free UK delivery on orders over £50. Orders are dispatched within 1-2 working days and typically arrive 1-2 working days later.
Return unused items in their original packaging within 30 days of delivery. Return postage is £3.50.
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Founded in California in 1974, Specialized began with a simple promise: serious riders deserve serious gear. Half a century later, the brand still funds its own wind tunnel, builds its own carbon, and tests every bike with the world's best so that you ride your own best.
The first production mountain bike. The first cycling-specific shoes. FACT carbon, the Win Tunnel, S-Works. Specialized has a habit of building the things the rest of cycling ends up copying.