2021 Specialized Demo Expert vs 2021 Trek Session AL 27.5 Frameset
The Trek Session AL 27.5 Frameset size closest to your S3 is the XL. Compare the XL instead
What changes on the Trek Session AL 27.5 Frameset
Compared with the Specialized Demo Expert in S3, the Trek Session AL 27.5 Frameset in L places the top of the head tube 29 mm lower and 14 mm further back, relative to the bottom bracket.
- Frame stack
- −29 mm
- Lower front end
- Frame reach
- −14 mm
- Shorter frame reach
- Wheelbase
- n/a
- One of the bikes has no number for this
- Head angle
- +1.4°
- Steeper: sharper steering
- Chainstays
- n/a
- One of the bikes has no number for this
The two frames
We can't draw these frames yet. The Specialized Demo Expert numbers we have for size S3 are missing the chainstay length and wheelbase. The numbers below still compare.
Geometry side by side
| Measurement | Specialized Demo Expert S3 | Trek Session AL 27.5 Frameset L | Difference |
|---|---|---|---|
| Reach | 446mm | 432 | −14 mm |
| Stack | 632mm | 603 | −29 mm |
| Head tube angle | 62.8° | 64.2° | +1.4° |
| Seat tube angle | 76.8° | not listed | |
| Seat tube length | 420mm | 456 | +36 mm |
| Head tube length | 105mm | 115 | +10 mm |
| Effective top tube | not listed | 614 | |
| Chainstay length | not listed | 443 | |
| Wheelbase | not listed | 1229 | |
| BB drop | not listed | 9 | |
| BB height | not listed | 364 | |
| Standover | not listed | 790 |
Differences are the Trek Session AL 27.5 Frameset minus the Specialized Demo Expert. Full charts: 2021 Specialized Demo Expert, 2021 Trek Session AL 27.5 Frameset.
Where each sits in its class
Specialized Demo ExpertTrek Session AL 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 AL 27.5 FramesetAL 27.5 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 BLCK DMND | not listed |
| Brake | SRAM Code RS | not listed |
| Stem | Specialized two-piece | not listed |
| Saddle | Specialized Henge DH | not listed |
| Frame | not listed | Trek Alpha Platinum |
| Headset | not listed | FSA Orbit |
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