2026 Trek Domane SL Gen 4 vs 2025 Specialized Roubaix SL8 Pro
The 44 is the Specialized Roubaix SL8 Pro size closest to your 47 Trek Domane SL Gen 4. We match frame stack and reach. This is a geometry comparison, not a fit recommendation; stem, spacers, handlebars and saddle setup also affect your riding position.
What changes on the Specialized Roubaix SL8 Pro
Compared with the Trek Domane SL Gen 4 in 47, the Specialized Roubaix SL8 Pro in 44 places the top of the head tube 16 mm higher and 11 mm further back, relative to the bottom bracket. Its wheelbase is 8 mm longer, which can contribute to stability at speed.
- Frame stack
- +16 mm
- Higher front end
- Frame reach
- −11 mm
- Shorter frame reach
- Wheelbase
- +8 mm
- Longer: steadier at speed
- Head angle
- −1.7°
- Slacker: calmer steering
- Chainstays
- −2 mm
- About the same
The two frames
Trek Domane SL Gen 4, 47Specialized Roubaix SL8 Pro, 44Drawn to scale and lined up at the bottom bracket.
Geometry side by side
| Measurement | Trek Domane SL Gen 4 47 | Specialized Roubaix SL8 Pro 44 | Difference |
|---|---|---|---|
| Reach | 364 | 353mm | −11 mm |
| Stack | 527 | 543mm | +16 mm |
| Head tube angle | 71.0 | 69.3° | −1.7° |
| Seat tube angle | 74.6 | 75° | +0.4° |
| Effective top tube | 509 | not listed | |
| Chainstay length | 420 | 418mm | −2 mm |
| Wheelbase | 986 | 994mm | +8 mm |
| BB drop | 80 | 80mm | ±0 mm |
| BB height | 256 | 269mm | +13 mm |
| Standover | 686 | 686mm | ±0 mm |
| Seat tube length | 420 | 365mm | −55 mm |
| Head tube length | 110 | 90mm | −20 mm |
| Fork length | not listed | 375mm |
Differences are the Specialized Roubaix SL8 Pro minus the Trek Domane SL Gen 4. Full charts: 2026 Trek Domane SL Gen 4, 2025 Specialized Roubaix SL8 Pro.
Where each sits in its class
Trek Domane SL Gen 4Specialized Roubaix SL8 Pro
Each bike is ranked against the other road bikes on Quiver, on frame geometry alone. Not your hand position or ride feel.
What each ships with
The stock build of each bike's first listed trim. Parts that match are dimmed.
| Part | Trek Domane SL Gen 4 | Specialized Roubaix SL8 ProSL8 Pro |
|---|---|---|
| Fork | not listed | Specialized Future Shock 3.3 |
| Shifter | not listed | Shimano Ultegra R8170 Di2 |
| Derailleur | not listed | Shimano Ultegra R8150 Di2 |
| Cassette | not listed | Shimano Ultegra |
| Chain | not listed | Shimano XT M8100 |
| Crankset | not listed | Shimano Ultegra R8100 |
| Wheelset | not listed | Roval Terra CL II |
| Tire | not listed | Specialized S-Works Mondo 2BR |
| Brake | not listed | Shimano Ultegra |
| Stem | not listed | Specialized Future |
| Seatpost | not listed | Specialized S-Works Pave Seat post |
| Saddle | not listed | Specialized Power Pro Mirror |
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