2021 Trek Session 27.5 vs 2023 Trek Session C 27.5 Frameset
The S is the Trek Session C 27.5 Frameset size closest to your M Trek Session 27.5. 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 Trek Session 27.5 in M, the Trek Session C 27.5 Frameset in S places the top of the head tube 13 mm higher and about as far forward, relative to the bottom bracket. Its wheelbase is 11 mm longer, which can contribute to stability at speed.
- Frame stack
- +13 mm
- Higher front end
- Frame reach
- +2 mm
- About the same reach
- Wheelbase
- +11 mm
- Longer: steadier at speed
- Head angle
- −0.7°
- Slacker: calmer steering
- Chainstays
- +2 mm
- About the same
The two frames
We can't draw these frames yet. The Trek Session 27.5 numbers we have for size M are missing the seat angle. The numbers below still compare.
Geometry side by side
| Measurement | Trek Session 27.5 M | Trek Session C 27.5 Frameset S | Difference |
|---|---|---|---|
| Reach | 408 | 410 | +2 mm |
| Stack | 603 | 616 | +13 mm |
| Head tube angle | 64.2° | 63.5° | −0.7° |
| Effective top tube | 590 | 579 | −11 mm |
| Chainstay length | 443 | 445 | +2 mm |
| Wheelbase | 1205 | 1216 | +11 mm |
| BB drop | 9 | 20 | +11 mm |
| BB height | 364 | 356 | −8 mm |
| Standover | 793 | 738 | −55 mm |
| Seat tube length | 426 | 425 | −1 mm |
| Head tube length | 115 | 115 | ±0 mm |
Differences are the Trek Session C 27.5 Frameset minus the Trek Session 27.5. Full charts: 2021 Trek Session 27.5, 2023 Trek Session C 27.5 Frameset.
Where each sits in its class
Trek Session 27.5Trek 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 | Trek Session 27.58 27.5 | Trek Session C 27.5 Frameset27.5 Frameset |
|---|---|---|
| Frame | Trek Alpha Platinum | Trek OCLV |
| Fork | RockShox BoXXer 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 | TruVativ Descendant DH | not listed |
| Bottom bracket | SRAM DUB | not listed |
| Pedals | Wellgo BO-87B | not listed |
| Wheelset | Bontrager Line DH 30 | not listed |
| Tire | Bontrager G4 Team Issue | not listed |
| Brake | SRAM Guide R | not listed |
| Handlebar | Bontrager Line | not listed |
| Stem | Bontrager Line | not listed |
| Headset | FSA Orbit | FSA Orbit |
| Seatpost | Bontrager Rhythm Elite | not listed |
| Saddle | Bontrager Arvada | not listed |
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