KYB AOS Compression Holders

KYB AOS Compression Base Valve Holder

This precision-machined steel compression base valve holder is a direct-fit replacement for all KYB AOS fork systems and addresses several critical shortcomings of the OEM component. The stock aluminum holder is prone to thread damage and failure, especially during repeated servicing. Additionally, the OEM design often leaves insufficient thread engagement when using performance-oriented shim stacks.

This issue is compounded by the factory peened threads, which, if improperly removed, can lead to galling, cross-threading, or damaged threads. More importantly, when stacking additional shims for custom valving, the remaining usable threads often fall below acceptable safety margins — leaving too little room to properly secure the nut, risking loosening or failure under load.

Our upgraded holder resolves these common issues by featuring:

• Precision-machined steel construction: Increased strength and service life.

• Extended 6×1 thread design: Provides greater thread engagement and additional clearance, specifically for taller or more aggressive shim stack configurations.

• Service-friendly design: Eliminates the need for factory peening. The included nylon locking nut ensures secure fastening without compromising the threads, allowing for clean, repeatable installation across multiple services.

Engineered for tuners and riders who demand reliability, serviceability, and peace of mind during aggressive riding and repeated maintenance cycles.

Applications:
Compatible with all AOS Front Forks, including:

• Yamaha YZ & YZF models

• Beta RR models equipped with AOS forks

• Stark Varg (2024 – 2025)

• Kawasaki KX250F (2020–2024)

• Suzuki RMZ250 (2020–2025)

*Sold In Pairs