The Shimano CS-7800 1mm Low Spacer is a small but essential drivetrain accessory designed to fine-tune cassette fit and alignment on compatible Shimano freehub systems. When adjusting wheel spacing or optimizing gear alignment, this low spacer helps ensure the cassette sits in the correct position relative to the derailleur and chainline — improving shifting precision and drivetrain performance.

Engineered to Shimano’s quality standards, the CS-7800 1mm spacer is made from durable material that maintains its thickness and shape under load. Its precise 1mm width is ideal for small adjustments when fine-tuning cassette placement, especially on road bikes that require exact spacing for smooth, reliable shifting. Whether you’re building a wheelset, correcting spacing after hub service, or ensuring ideal alignment for a multi-speed drivetrain, this spacer helps you achieve consistent performance.

Installation is simple — the spacer fits onto the freehub body before cassette installation to correct spacing as needed. The Shimano CS-7800 1mm Low Spacer is an easy, cost-effective solution for addressing minor alignment issues that can otherwise compromise shift quality and drivetrain efficiency.