2021 Trek Session C 27.5 Frameset vs 2023 Specialized Demo Expert
The S2 is the Specialized Demo Expert size closest to your M Trek Session C 27.5 Frameset. 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 Demo Expert
Compared with the Trek Session C 27.5 Frameset in M, the Specialized Demo Expert in S2 places the top of the head tube 16 mm higher and 3 mm further back, relative to the bottom bracket. Its wheelbase is 4 mm longer, which can contribute to stability at speed.
- Frame stack
- +16 mm
- Higher front end
- Frame reach
- −3 mm
- Shorter frame reach
- Wheelbase
- +4 mm
- Longer: steadier at speed
- Head angle
- −0.7°
- Slacker: calmer steering
- Chainstays
- +3 mm
- Longer: more planted
The two frames
We can't draw these frames yet. The Trek Session C 27.5 Frameset numbers we have for size M are missing the seat angle. The numbers below still compare.
Geometry side by side
| Measurement | Trek Session C 27.5 Frameset M | Specialized Demo Expert S2 | Difference |
|---|---|---|---|
| Reach | 429 | 426mm | −3 mm |
| Stack | 616 | 632mm | +16 mm |
| Head tube angle | 63.5° | 62.8° | −0.7° |
| Effective top tube | 584 | not listed | |
| Chainstay length | 445 | 448mm | +3 mm |
| Wheelbase | 1235 | 1239mm | +4 mm |
| BB drop | 20 | not listed | |
| BB height | 356 | not listed | |
| Standover | not listed | not listed | |
| Seat tube length | 425 | 394mm | −31 mm |
| Head tube length | 115 | 105mm | −10 mm |
| Seat tube angle | not listed | 78.2° |
Differences are the Specialized Demo Expert minus the Trek Session C 27.5 Frameset. Full charts: 2021 Trek Session C 27.5 Frameset, 2023 Specialized Demo Expert.
Where each sits in its class
Trek Session C 27.5 FramesetSpecialized Demo Expert
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 | Trek Session C 27.5 Frameset27.5 Frameset | Specialized Demo ExpertExpert |
|---|---|---|
| Frame | Trek OCLV | not listed |
| Headset | FSA Orbit | not listed |
| Fork | not listed | RockShox BoXXer 29 |
| Rear shock | not listed | RockShox Super Deluxe Select |
| Shifter | not listed | SRAM GX DH |
| Derailleur | not listed | SRAM GX DH |
| Cassette | not listed | SRAM GX DH |
| Chain | not listed | SRAM PC1110 |
| Crankset | not listed | Specialized DESCENDANT DH |
| Bottom bracket | not listed | SRAM DUB |
| Tire | not listed | Specialized Butcher |
| Brake | not listed | SRAM Code RS |
| Stem | not listed | Specialized Descendant |
| Saddle | not listed | Specialized Henge DH |
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