2024 Specialized Roubaix SL8 FACT 12R Carbon vs 2025 Trek Domane AL 4 Gen 4
The 49 is the Trek Domane AL 4 Gen 4 size closest to your 44 Specialized Roubaix SL8 FACT 12R Carbon. 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 Trek Domane AL 4 Gen 4
Compared with the Specialized Roubaix SL8 FACT 12R Carbon in 44, the Trek Domane AL 4 Gen 4 in 49 places the top of the head tube 3 mm lower and 15 mm further forward, relative to the bottom bracket. Its wheelbase is 7 mm longer, which can contribute to stability at speed.
- Frame stack
- −3 mm
- Lower front end
- Frame reach
- +15 mm
- Longer frame reach
- Wheelbase
- +7 mm
- Longer: steadier at speed
- Head angle
- +1.5°
- Steeper: sharper steering
- Chainstays
- +7 mm
- Longer: more planted
The two frames
Only the Specialized Roubaix SL8 FACT 12R Carbon is drawn. The Trek Domane AL 4 Gen 4 numbers we have for size 49 are missing the seat angle.
Geometry side by side
| Measurement | Specialized Roubaix SL8 FACT 12R Carbon 44 | Trek Domane AL 4 Gen 4 49 | Difference |
|---|---|---|---|
| Reach | 353mm | 368 | +15 mm |
| Stack | 543mm | 540 | −3 mm |
| Head tube angle | 69.3° | 70.8° | +1.5° |
| Seat tube angle | 75° | not listed | |
| Chainstay length | 418mm | 425 | +7 mm |
| Wheelbase | 994mm | 1001 | +7 mm |
| BB drop | 80mm | 80 | ±0 mm |
| BB height | 269mm | not listed | |
| Standover | 686mm | 717 | +31 mm |
| Seat tube length | 365mm | 440 | +75 mm |
| Fork length | 375mm | not listed | |
| Head tube length | 90mm | 123 | +33 mm |
| Effective top tube | not listed | 516 |
Differences are the Trek Domane AL 4 Gen 4 minus the Specialized Roubaix SL8 FACT 12R Carbon. Full charts: 2024 Specialized Roubaix SL8 FACT 12R Carbon, 2025 Trek Domane AL 4 Gen 4.
Where each sits in its class
Specialized Roubaix SL8 FACT 12R CarbonTrek Domane AL 4 Gen 4
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 | Specialized Roubaix SL8 FACT 12R CarbonS-Works SL8 FACT 12R Carbon | Trek Domane AL 4 Gen 4Gen 4 |
|---|---|---|
| Fork | Specialized Future Shock 3.3 | Trek Domane AL |
| Seatpost | Specialized S-Works Pave Seat post | Bontrager Comp |
| Frame | not listed | Trek Domane AL |
| Shifter | not listed | Shimano Tiagra |
| Derailleur | not listed | Shimano Tiagra |
| Cassette | not listed | Shimano HG500 |
| Chain | not listed | Shimano HG54 Tiagra |
| Crankset | not listed | Shimano Tiagra |
| Chainring | not listed | Shimano Tiagra |
| Bottom bracket | not listed | Shimano RS501 |
| Wheelset | not listed | Bontrager Paradigm 23 |
| Tire | not listed | Bontrager Kwaremont Comp |
| Hub | not listed | Formula RX-512, Formula RX-142 |
| Rim | not listed | Bontrager Paradigm SL |
| Brake | not listed | Shimano Tiagra |
| Rotor | not listed | Shimano SM-RT66 |
| Handlebar | not listed | Bontrager Comp |
| Stem | not listed | Bontrager Elite |
| Bar tape | not listed | Bontrager Supertack Performance |
| Saddle | not listed | Bontrager Verse Short |
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