2017 Specialized Demo II Alloy vs 2019 Trek Session C 27.5 Frameset
The S is the Trek Session C 27.5 Frameset size closest to your SHORT Specialized Demo II Alloy. 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 II Alloy in SHORT, the Trek Session C 27.5 Frameset in S places the top of the head tube at about the same height and 15 mm further forward, relative to the bottom bracket. Its wheelbase is 33 mm longer, which can contribute to stability at speed.
- Frame stack
- +2 mm
- About the same height
- Frame reach
- +15 mm
- Longer frame reach
- Wheelbase
- +33 mm
- Longer: steadier at speed
- Head angle
- ±0.0°
- About the same head angle
- Chainstays
- +15 mm
- Longer: more planted
The two frames
Only the Specialized Demo II Alloy is drawn. The Trek Session C 27.5 Frameset numbers we have for size S are missing the seat angle.
Geometry side by side
| Measurement | Specialized Demo II Alloy SHORT | Trek Session C 27.5 Frameset S | Difference |
|---|---|---|---|
| Reach | 395mm | 410 | +15 mm |
| Stack | 614mm | 616 | +2 mm |
| Head tube angle | 63.5° | 63.5° | ±0.0° |
| Seat tube angle | 74° | not listed | |
| Effective top tube | 571mm | 579 | +8 mm |
| Chainstay length | 430mm | 445 | +15 mm |
| Wheelbase | 1183mm | 1216 | +33 mm |
| BB drop | 12mm | 20 | +8 mm |
| BB height | 342mm | 356 | +14 mm |
| Standover | 698mm | 738 | +40 mm |
| Seat tube length | 367mm | 425 | +58 mm |
| Head tube length | 105mm | 115 | +10 mm |
Differences are the Trek Session C 27.5 Frameset minus the Specialized Demo II Alloy. Full charts: 2017 Specialized Demo II Alloy, 2019 Trek Session C 27.5 Frameset.
Where each sits in its class
Specialized Demo II AlloyTrek 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 II Alloy8 II Alloy | Trek Session C 27.5 Frameset27.5 Frameset |
|---|---|---|
| Fork | RockShox Boxxer Team | not listed |
| Rear shock | Öhlins TTX | not listed |
| Shifter | SRAM X9 | not listed |
| Derailleur | SRAM X0 | not listed |
| Cassette | SRAM PG-1030 | not listed |
| Chain | SRAM PC-1031 | not listed |
| Crankset | SRAM X0 DH | not listed |
| Pedals | Specialized Bennies | not listed |
| Tire | Specialized Slaughter, Specialized Butcher | not listed |
| Hub | DT Swiss 350 | not listed |
| Brake | SRAM Guide RS | not listed |
| Stem | Specialized P.Series | not listed |
| Grips | Specialized Sip Grip | not listed |
| Saddle | Specialized Phenom Comp | not listed |
| Frame | not listed | Trek OCLV |
| Headset | not listed | FSA Orbit |
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