The SRAM X01 DH X-HORIZON is a single-speed rear derailleur built for downhill — chain guide function only, no indexing, designed to keep the chain on the single chainring under the harshest DH conditions. X-HORIZON geometry keeps the derailleur arm position consistent regardless of chain tension, reducing chain slap and maintaining clean chain line on the steepest terrain.

Highlights

• Single-speed DH rear derailleur — chain guide/tensioner function only
• X-HORIZON parallel arm geometry for consistent chain line
• X01 DH level — built for downhill racing and freeride loads
• Robust construction to withstand impacts and rough terrain
• Compatible with SRAM DH chains and single-speed DH drivetrains

X-HORIZON geometry

Standard rear derailleurs swing in an arc as the chain tension varies — on DH bikes, this causes inconsistency in chain tension through big hits and drops. X-HORIZON uses a linkage geometry where the derailleur arm moves more horizontally than a traditional parallelogram, keeping chain tension consistent regardless of suspension travel and terrain impact.

Fit and compatibility

Single-speed DH rear derailleur. Designed for 1x DH drivetrains with a single chainring. Confirm frame derailleur hanger compatibility and chain size before ordering.