Genetic

Seatpost Shim 30.9mm to 31.6mm

The Genetic Seatpost Shim 30.9mm to 31.6mm makes dialing in the perfect fit simple and secure. Designed for riders who want to run their favorite 30.9mm post in a 31.6mm frame, this shim ensures a snug, creak-free fit without compromising performance or safety.

Precision CNC machining delivers a clean, exact interface that keeps your seatpost firmly in place on rough trails and long road rides alike. Its extended length adds stability, reducing stress on your frame and post while preventing unwanted movement over time. The integrated top lip makes installation straightforward and reliable—no slipping, no guessing, just clean performance.

Key Features:

• Fits 30.9mm seatposts into 31.6mm seat tubes
• Long shim length for extra frame and post protection
• Precision CNC machined alloy for a perfect, rattle-free fit
• Top lip design for easy installation and secure positioning

Whether you’re building up a custom ride or fine-tuning your bike fit, the Genetic Seatpost Shim provides a lightweight, dependable solution that feels factory-perfect every time.