2017 Specialized Demo II Alloy vs 2015 Trek Session DH 27.5

What changes on the Trek Session DH 27.5

Compared with the Specialized Demo II Alloy in SHORT, the Trek Session DH 27.5 in XL places the top of the head tube 11 mm lower and 61 mm further forward, relative to the bottom bracket. Its wheelbase is 70 mm longer, which can contribute to stability at speed.

Frame stack

−11 mm

Lower front end

Frame reach

+61 mm

Longer frame reach

Wheelbase

+70 mm

Longer: steadier at speed

Head angle

+0.7°

Steeper: sharper steering

Chainstays

+13 mm

Longer: more planted

The two frames

Only the Specialized Demo II Alloy is drawn. The Trek Session DH 27.5 numbers we have for size XL are missing the seat angle.

Geometry side by side

Differences are the Trek Session DH 27.5 minus the Specialized Demo II Alloy. Full charts: 2017 Specialized Demo II Alloy, 2015 Trek Session DH 27.5.

Where each sits in its class

Specialized Demo II AlloyTrek Session DH 27.5

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.