2020 Trek Session AL 27.5 Frameset vs 2022 Specialized Demo Expert
The Specialized Demo Expert size closest to your M is the S2. Compare the S2 instead
What changes on the Specialized Demo Expert
Compared with the Trek Session AL 27.5 Frameset in M, the Specialized Demo Expert in S4 places the top of the head tube 29 mm higher and 58 mm further forward, relative to the bottom bracket. Its wheelbase is 74 mm longer, which can contribute to stability at speed.
- Frame stack
- +29 mm
- Higher front end
- Frame reach
- +58 mm
- Longer frame reach
- Wheelbase
- +74 mm
- Longer: steadier at speed
- Head angle
- −1.4°
- Slacker: calmer steering
- Chainstays
- +5 mm
- Longer: more planted
The two frames
We can't draw these frames yet. The Trek Session AL 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 AL 27.5 Frameset M | Specialized Demo Expert S4 | Difference |
|---|---|---|---|
| Reach | 408 | 466mm | +58 mm |
| Stack | 603 | 632mm | +29 mm |
| Head tube angle | 64.2° | 62.8° | −1.4° |
| Effective top tube | 590 | not listed | |
| Chainstay length | 443 | 448mm | +5 mm |
| Wheelbase | 1205 | 1279mm | +74 mm |
| BB drop | 9 | not listed | |
| BB height | 364 | not listed | |
| Standover | 793 | not listed | |
| Seat tube length | 426 | 420mm | −6 mm |
| Head tube length | 115 | 105mm | −10 mm |
| Seat tube angle | not listed | 76.8° |
Differences are the Specialized Demo Expert minus the Trek Session AL 27.5 Frameset. Full charts: 2020 Trek Session AL 27.5 Frameset, 2022 Specialized Demo Expert.
Where each sits in its class
Trek Session AL 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 AL 27.5 FramesetAL 27.5 Frameset | Specialized Demo ExpertExpert |
|---|---|---|
| Frame | Trek Alpha Platinum | 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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