2026 Specialized Roubaix SL8 Sport vs 2027 Trek Domane AL 4 Gen 4
The 56 is the Trek Domane AL 4 Gen 4 size closest to your 54 Specialized Roubaix SL8 Sport. 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 Sport in 54, the Trek Domane AL 4 Gen 4 in 56 places the top of the head tube 6 mm higher and 4 mm further back, relative to the bottom bracket.
- Frame stack
- +6 mm
- Higher front end
- Frame reach
- −4 mm
- Shorter frame reach
- Wheelbase
- n/a
- One of the bikes has no number for this
- Head angle
- −0.4°
- Slacker: calmer steering
- Chainstays
- ±0 mm
- About the same
The two frames
We can't draw these frames yet. The Specialized Roubaix SL8 Sport numbers we have for size 54 are missing the wheelbase. The numbers below still compare.
Geometry side by side
| Measurement | Specialized Roubaix SL8 Sport 54 | Trek Domane AL 4 Gen 4 56 | Difference |
|---|---|---|---|
| Reach | 381 | 377 | −4 mm |
| Stack | 585 | 591 | +6 mm |
| Head tube angle | 72.3 | 71.9 | −0.4° |
| Seat tube angle | 74 | 73.3 | −0.7° |
| Effective top tube | 550 | 554 | +4 mm |
| Chainstay length | 420 | 420 | ±0 mm |
| BB drop | 78 | 78 | ±0 mm |
| BB height | 270 | not listed | |
| Standover | 766 | 776 | +10 mm |
| Seat tube length | 465 | 525 | +60 mm |
| Fork length | 375 | not listed | |
| Head tube length | 122 | 175 | +53 mm |
| Wheelbase | not listed | 1018 |
Differences are the Trek Domane AL 4 Gen 4 minus the Specialized Roubaix SL8 Sport. Full charts: 2026 Specialized Roubaix SL8 Sport, 2027 Trek Domane AL 4 Gen 4.
Where each sits in its class
Specialized Roubaix SL8 SportTrek 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 SportSL8 Sport | Trek Domane AL 4 Gen 4Gen 4 |
|---|---|---|
| Frame | Specialized FACT 10R | Trek Domane AL |
| Fork | Specialized Future Shock 3.2 | Trek Domane AL |
| Shifter | Shimano 105 R7120 | Shimano Tiagra R4020 |
| Derailleur | Shimano 105 Di2, Shimano 105 R7100 | Shimano Tiagra R4000, Shimano Tiagra 4700 |
| Cassette | Shimano 105 | Shimano RS400 |
| Chain | Shimano SLX M7100 | Shimano LG500 |
| Crankset | Shimano 105 | Shimano Tiagra R4000 |
| Bottom bracket | Shimano Threaded BSA | Shimano RS501 |
| Wheelset | DT Swiss G540 | Bontrager Paradigm 23 |
| Tire | Specialized Mondo | Bontrager Kwaremont |
| Brake | Shimano CUES | not listed |
| Handlebar | Specialized Hover | Bontrager Comp |
| Stem | Specialized Future Pro | Bontrager Elite |
| Grips | Supacaz Super Sticky Kush | not listed |
| Seatpost | Specialized Pavé | Bontrager Comp |
| Saddle | Specialized Power Sport | Trek Verse Short |
| Chainring | not listed | Shimano Tiagra 4700 |
| Hub | not listed | Formula RX-142, Formula RX-512 |
| Rim | not listed | Bontrager Paradigm 23 |
| Rotor | not listed | Shimano SM-RT66 |
| Bar tape | not listed | Bontrager Supertack Perf |
| Headset | not listed | Bontrager Expander Plug |
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