Quiver

2017 Specialized Demo I Carbon vs 2019 Trek Session C 27.5 Frameset

The Trek Session C 27.5 Frameset size closest to your SHORT is the S. Compare the S instead

What changes on the Trek Session C 27.5 Frameset

Compared with the Specialized Demo I Carbon in SHORT, the Trek Session C 27.5 Frameset in L places the top of the head tube at about the same height and 55 mm further forward, relative to the bottom bracket. Its wheelbase is 73 mm longer, which can contribute to stability at speed.

Frame stack
+2 mm
About the same height
Frame reach
+55 mm
Longer frame reach
Wheelbase
+73 mm
Longer: steadier at speed
Head angle
±0.0°
About the same head angle
Chainstays
+15 mm
Longer: more planted

The two frames

2017 Specialized Demo I Carbon (SHORT)The Specialized Demo I Carbon frame drawn to scale.J 1183

Only the Specialized Demo I Carbon is drawn. The Trek Session C 27.5 Frameset numbers we have for size L are missing the seat angle.

Geometry side by side

MeasurementSpecialized Demo I Carbon SHORTTrek Session C 27.5 Frameset LDifference
Reach395mm450+55 mm
Stack614mm616+2 mm
Head tube angle63.5°63.5°±0.0°
Seat tube angle74°not listed
Effective top tube571mm606+35 mm
Chainstay length430mm445+15 mm
Wheelbase1183mm1256+73 mm
BB drop12mm20+8 mm
BB height342mm356+14 mm
Standover698mm746+48 mm
Seat tube length367mm456+89 mm
Head tube length105mm115+10 mm

Differences are the Trek Session C 27.5 Frameset minus the Specialized Demo I Carbon. Full charts: 2017 Specialized Demo I Carbon, 2019 Trek Session C 27.5 Frameset.

Where each sits in its class

Specialized Demo I CarbonTrek Session C 27.5 Frameset

AggressivePositionUpright
CalmSteeringQuick
PlayfulBalancePlanted

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.

PartSpecialized Demo I Carbon8 I CarbonTrek Session C 27.5 Frameset27.5 Frameset
ForkRockShox BoXXer RCnot listed
Rear shockÖhlins TTXnot listed
ShifterSRAM GXnot listed
DerailleurSRAM GX DHnot listed
CassetteSRAM GX DHnot listed
ChainSRAM PC-1110not listed
CranksetSRAM Descendantnot listed
PedalsSpecialized Benniesnot listed
TireSpecialized Butcher, Specialized Slaughternot listed
HubSpecialized spacingnot listed
BrakeSRAM Guide Rnot listed
StemSpecialized P.Seriesnot listed
GripsSpecialized Sip Gripnot listed
SaddleSpecialized Phenom Compnot listed
Framenot listedTrek OCLV
Headsetnot listedFSA Orbit

Know what is on every bike.

Add your bike to Quiver. Keep its parts, setup, and service history together, then share your build.

Explore the app
A Transition Relay build sheet: frame, fork, shock and drivetrainThe Relay’s ride photo galleryThe Relay’s ride spectrum and 2D frame geometryThe garage: five bikes and 99 recorded partsA Specialized Tarmac SL8 road build sheet