2027 Trek Domane AL 4 Gen 4 vs 2025 Specialized Roubaix SL8 Pro
The 49 is the Specialized Roubaix SL8 Pro size closest to your 49 Trek Domane AL 4 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 AL 4 Gen 4 in 49, the Specialized Roubaix SL8 Pro in 49 places the top of the head tube 9 mm higher and 5 mm further back, relative to the bottom bracket. Its wheelbase is 9 mm shorter, which can contribute to quicker direction changes.
- Frame stack
- +9 mm
- Higher front end
- Frame reach
- −5 mm
- Shorter frame reach
- Wheelbase
- −9 mm
- Shorter: quicker to change direction
- Head angle
- ±0.0°
- About the same head angle
- Chainstays
- −7 mm
- Shorter: livelier
The two frames
Trek Domane AL 4 Gen 4, 49Specialized Roubaix SL8 Pro, 49Drawn to scale and lined up at the bottom bracket.
Geometry side by side
| Measurement | Trek Domane AL 4 Gen 4 49 | Specialized Roubaix SL8 Pro 49 | Difference |
|---|---|---|---|
| Reach | 368 | 363mm | −5 mm |
| Stack | 540 | 549mm | +9 mm |
| Head tube angle | 70.8 | 70.8° | ±0.0° |
| Seat tube angle | 74.6 | 74° | −0.6° |
| Effective top tube | 516 | not listed | |
| Chainstay length | 425 | 418mm | −7 mm |
| Wheelbase | 1001 | 992mm | −9 mm |
| BB drop | 80 | 80mm | ±0 mm |
| Standover | 717 | 719mm | +2 mm |
| Seat tube length | 440 | 410mm | −30 mm |
| Head tube length | 123 | 90mm | −33 mm |
| BB height | not listed | 269mm | |
| Fork length | not listed | 375mm |
Differences are the Specialized Roubaix SL8 Pro minus the Trek Domane AL 4 Gen 4. Full charts: 2027 Trek Domane AL 4 Gen 4, 2025 Specialized Roubaix SL8 Pro.
Where each sits in its class
Trek Domane AL 4 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 AL 4 Gen 4Gen 4 | Specialized Roubaix SL8 ProSL8 Pro |
|---|---|---|
| Frame | Trek Domane AL | not listed |
| Fork | Trek Domane AL | Specialized Future Shock 3.3 |
| Shifter | Shimano Tiagra R4020 | Shimano Ultegra R8170 Di2 |
| Derailleur | Shimano Tiagra R4000, Shimano Tiagra 4700 | Shimano Ultegra R8150 Di2 |
| Cassette | Shimano RS400 | Shimano Ultegra |
| Chain | Shimano LG500 | Shimano XT M8100 |
| Crankset | Shimano Tiagra R4000 | Shimano Ultegra R8100 |
| Chainring | Shimano Tiagra 4700 | not listed |
| Bottom bracket | Shimano RS501 | not listed |
| Wheelset | Bontrager Paradigm 23 | Roval Terra CL II |
| Tire | Bontrager Kwaremont | Specialized S-Works Mondo 2BR |
| Hub | Formula RX-142, Formula RX-512 | not listed |
| Rim | Bontrager Paradigm 23 | not listed |
| Rotor | Shimano SM-RT66 | not listed |
| Handlebar | Bontrager Comp | not listed |
| Stem | Bontrager Elite | Specialized Future |
| Bar tape | Bontrager Supertack Perf | not listed |
| Headset | Bontrager Expander Plug | not listed |
| Seatpost | Bontrager Comp | Specialized S-Works Pave Seat post |
| Saddle | Trek Verse Short | Specialized Power Pro Mirror |
| Brake | not listed | Shimano Ultegra |
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