2024 Specialized Tarmac SL8 Pro Shimano vs 2026 Trek Madone SLR Gen 8
The XS is the Trek Madone SLR Gen 8 size closest to your 44 Specialized Tarmac SL8 Pro Shimano. 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 Madone SLR Gen 8
Compared with the Specialized Tarmac SL8 Pro Shimano in 44, the Trek Madone SLR Gen 8 in XS places the top of the head tube at about the same height and 7 mm further forward, relative to the bottom bracket.
- Frame stack
- −2 mm
- About the same height
- Frame reach
- +7 mm
- Longer frame reach
- Wheelbase
- +1 mm
- About the same
- Head angle
- +1.1°
- Steeper: sharper steering
- Chainstays
- ±0 mm
- About the same
The two frames
Only the Specialized Tarmac SL8 Pro Shimano is drawn. The Trek Madone SLR Gen 8 numbers we have for size XS are missing the seat angle.
Geometry side by side
| Measurement | Specialized Tarmac SL8 Pro Shimano 44 | Trek Madone SLR Gen 8 XS | Difference |
|---|---|---|---|
| Reach | 363mm | 370 | +7 mm |
| Stack | 509mm | 507 | −2 mm |
| Head tube angle | 70.5° | 71.6° | +1.1° |
| Seat tube angle | 75.5° | not listed | |
| Chainstay length | 410mm | 410 | ±0 mm |
| Wheelbase | 970mm | 971 | +1 mm |
| BB drop | 74mm | 72 | −2 mm |
| BB height | 266mm | not listed | |
| Standover | 723mm | 704 | −19 mm |
| Seat tube length | 433mm | 404 | −29 mm |
| Fork length | 370mm | not listed | |
| Head tube length | 99mm | 100 | +1 mm |
| Effective top tube | not listed | 517 |
Differences are the Trek Madone SLR Gen 8 minus the Specialized Tarmac SL8 Pro Shimano. Full charts: 2024 Specialized Tarmac SL8 Pro Shimano, 2026 Trek Madone SLR Gen 8.
Where each sits in its class
Specialized Tarmac SL8 Pro ShimanoTrek Madone SLR Gen 8
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 Tarmac SL8 Pro ShimanoPro - Shimano Ultegra Di2 | Trek Madone SLR Gen 8SLR 7 AXS Gen 8 |
|---|---|---|
| Frame | Specialized Tarmac SL8 FACT | not listed |
| Shifter | Shimano Ultegra R8170 Di2 | not listed |
| Derailleur | Shimano Ultegra R8150 Di2 | not listed |
| Cassette | Shimano Ultegra | not listed |
| Chain | Shimano Ultegra | not listed |
| Crankset | Shimano Ultegra R8100 | not listed |
| Wheelset | Roval Rapide CL II | Bontrager Aeolus Pro 51 |
| Tire | Specialized S-Works Turbo | Pirelli P Zero |
| Brake | Shimano Ultegra R8170 Di2 | not listed |
| Handlebar | Roval Rapide | Trek RSL |
| Seatpost | Specialized S-Works Tarmac SL8 | not listed |
| Saddle | Specialized Power | not listed |
| Fork | not listed | Trek Madone Gen 8 one-piece |
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