Campagnolo N3W Cassette Adapter & Lockring Kit (AC21‑N3W) – Enables 10/11/12‑Speed Cassettes with 11T Start on N3W Freehub Bodies

• Enables 11T‑Start Cassettes on N3W Freehubs – Restores the correct freehub length for mounting 10‑, 11‑ and 12‑speed Campagnolo cassettes with an 11‑tooth first sprocket
• Essential for Backward Compatibility – Allows modern N3W freehubs to work with classic Campagnolo drivetrain systems
• Complete Installation Kit – Includes adapter, metal extension ring, and dedicated long lockring required for correct cassette tightening
• Not Required for 9T/10T Systems – Separator is unnecessary for Ekar and Wireless cassettes designed specifically for N3W bodies
• Genuine Campagnolo Component – Manufactured to OE specifications for perfect fit, durability, and shifting precision
• Campagnolo Part Code: AC21-N3W

The Campagnolo AC21 N3W Adapter Kit is designed to ensure full backward compatibility between the Campagnolo N3W freehub body and traditional cassettes that start with an 11 tooth sprocket. The N3W freehub standard is shorter than the classic Campagnolo body, and this adapter restores the correct length to allow proper installation of older 10 , 11 and 12 speed cassettes. This kit includes the adapter sleeve, a metal extension ring, and a specific longer lockring, which is essential because standard cassette lockrings do not reach the internal thread of the shorter N3W body. With this adapter installed, wheels equipped with the N3W freehub can safely and correctly mount legacy Campagnolo cassette systems. The AC21 N3W adapter is not required for newer cassettes that already use 9 or 10 tooth starting sprockets (such as Campagnolo Ekar or Wireless 12 speed systems), but it is indispensable for riders transitioning between groupsets or maintaining compatibility across multiple drivetrain setups. Designed and manufactured to Campagnolo’s precision standards, this kit ensures flawless shifting, secure cassette engagement, and long term reliability.