2023 Specialized Demo Expert vs 2023 Trek Session C 27.5 Frameset
The XL is the Trek Session C 27.5 Frameset size closest to your S4 Specialized Demo Expert. 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 Session C 27.5 Frameset
Compared with the Specialized Demo Expert in S4, the Trek Session C 27.5 Frameset in XL places the top of the head tube 16 mm lower and 9 mm further forward, relative to the bottom bracket.
- Frame stack
- −16 mm
- Lower front end
- Frame reach
- +9 mm
- Longer frame reach
- Wheelbase
- +2 mm
- About the same
- Head angle
- +0.7°
- Steeper: sharper steering
- Chainstays
- −3 mm
- Shorter: livelier
The two frames
Only the Specialized Demo Expert is drawn. The Trek Session C 27.5 Frameset numbers we have for size XL are missing the seat angle.
Geometry side by side
| Measurement | Specialized Demo Expert S4 | Trek Session C 27.5 Frameset XL | Difference |
|---|---|---|---|
| Reach | 466mm | 475 | +9 mm |
| Stack | 632mm | 616 | −16 mm |
| Head tube angle | 62.8° | 63.5° | +0.7° |
| Seat tube angle | 76.8° | not listed | |
| Chainstay length | 448mm | 445 | −3 mm |
| Wheelbase | 1279mm | 1281 | +2 mm |
| Seat tube length | 420mm | 456 | +36 mm |
| Head tube length | 105mm | 115 | +10 mm |
| Effective top tube | not listed | 631 | |
| BB drop | not listed | 20 | |
| BB height | not listed | 356 | |
| Standover | not listed | 748 |
Differences are the Trek Session C 27.5 Frameset minus the Specialized Demo Expert. Full charts: 2023 Specialized Demo Expert, 2023 Trek Session C 27.5 Frameset.
Where each sits in its class
Specialized Demo ExpertTrek Session C 27.5 Frameset
Each bike is ranked against the other downhill 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 Demo ExpertExpert | Trek Session C 27.5 Frameset27.5 Frameset |
|---|---|---|
| Fork | RockShox BoXXer 29 | not listed |
| Rear shock | RockShox Super Deluxe Select | not listed |
| Shifter | SRAM GX DH | not listed |
| Derailleur | SRAM GX DH | not listed |
| Cassette | SRAM GX DH | not listed |
| Chain | SRAM PC1110 | not listed |
| Crankset | Specialized DESCENDANT DH | not listed |
| Bottom bracket | SRAM DUB | not listed |
| Tire | Specialized Butcher | not listed |
| Brake | SRAM Code RS | not listed |
| Stem | Specialized Descendant | not listed |
| Saddle | Specialized Henge DH | not listed |
| Frame | not listed | Trek OCLV |
| Headset | not listed | FSA Orbit |
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