2017 Trek Session DH 27.5 vs 2019 Specialized Demo Alloy 27.5

What changes on the Specialized Demo Alloy 27.5

Compared with the Trek Session DH 27.5 in M, the Specialized Demo Alloy 27.5 in LONG places the top of the head tube 11 mm higher and 32 mm further forward, relative to the bottom bracket. Its wheelbase is 23 mm longer, which can contribute to stability at speed.

Frame stack

+11 mm

Higher front end

Frame reach

+32 mm

Longer frame reach

Wheelbase

+23 mm

Longer: steadier at speed

Head angle

−0.7°

Slacker: calmer steering

Chainstays

−13 mm

Shorter: livelier

The two frames

We can't draw these frames yet. The Trek Session DH 27.5 numbers we have for size M are missing the seat angle. The numbers below still compare.

Geometry side by side

Differences are the Specialized Demo Alloy 27.5 minus the Trek Session DH 27.5. Full charts: 2017 Trek Session DH 27.5, 2019 Specialized Demo Alloy 27.5.

Where each sits in its class

Trek Session DH 27.5Specialized Demo Alloy 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.