Zipp RT Lockring Internal Spline

SRAM and Zipp offer rotors and wheels, respectively, that are compatible with the Center Lock disc rotor mounting system developed by Shimano. Center Lock offers a secure hold and a perfect fit with fully compatible rotors, making it simple to remove and install a rotor. Most road and gravel disc brake wheelsets feature the Center Lock spline system. These Zipp Center Lock Disc Lock Rings are referred to as the external serration design and are meant to interface with a 16T/44-45mm (OD) external bottom bracket tool.

Zipp is offering two versions, one for 140mm and 160mm rotors (common for road and gravel bikes), and a second for rotors from 170-203mm sizes (most common on mountain bikes). Both are machined from aluminum and feature a floating stainless steel washer on the hub interface side.