Shimano Centerlock lockring for thru axles
The Shimano SM-HB20 Centerlock lockring reliably secures your brake rotor to hubs with 15 or 20 mm thru-axles and ensures a solid, confidence-inspiring braking feel on any trail. It combines low weight with high stability, making it the ideal choice for sporty riders who want to rely completely on their equipment.
Secure brake disc mounting for modern thru axles
The lightweight aluminum Centerlock lockring secures Centerlock brake rotors to hubs with 15 mm or 20 mm thru-axles, replacing conventional internal splined rings that are often inaccessible with thru-axles. Thanks to its external splines, the ring can be easily tightened with a standard Hollowtech II bottom bracket tool (e.g., TL-FC36/TL-FC32), ensuring a secure, play-free connection between the hub and brake rotor.
Lightweight, robust and versatilely compatible
Made from high-quality 6061 aluminum, the lockring offers an attractive weight-to-stiffness ratio of approximately 10 g. It is compatible with a wide range of Centerlock hubs from Shimano, DT Swiss, Fulcrum, Mavic, and other brands, and is particularly recommended for front hubs with 15 mm and 20 mm thru-axles.
Perfect for ambitious trail and all-mountain riders
Especially on challenging descents or in bike parks, the sturdy lockring ensures that your brake disc stays where it belongs – even under high thermal and mechanical stress. Its robust construction and ease of use make it a favorite for anyone who frequently tinkers, uses different wheelsets, or regularly adjusts their setup.
specification
| feature | Description |
|---|
| Application | Fixing Centerlock brake discs to thru-axle hubs |
| execution | External locking ring with external tool holder |
| Color | Black |
| Weight | Approx. 10 g |
| Hub compatibility | Centerlock hubs, especially Shimano 15/20 mm front thru-axle hubs, including XT, SLX, ZEE, as well as many DT Swiss, Fulcrum, and Mavic Centerlock hubs. |
| Thru-axle compatibility | 15 mm and 20 mm stub axles; especially for situations where internal gear rings are inaccessible. |
| Compatible tool | Hollowtech II bottom bracket wrench, e.g. Shimano TL-FC36 or TL-FC32 |
| material | 6061 Aluminium |
| Assembly | External teeth for secure screw fastening and high power transmission |
| Product type | Centerlock locking ring |
| Manufacturer part number | ASMHB20 / A-SMHB20 (sometimes listed as Y-26L98030) |
Scope of delivery
- 1 x Shimano SM-HB20 Centerlock external lockring
- 1 x washer for brake disc mounting
Here's what we think about it
The Centerlock lockring is described by many users as a reliable and straightforward solution for securely mounting brake discs to thru-axle hubs. One rider praised the ring, saying it was "made for this job" and noticeably improves the system because everything feels solid and free of play.
Another user emphasizes that the lockring is practically indispensable, especially with 15mm thru-axles, for the proper installation of a Centerlock brake rotor. Overall, the product is perceived as robust, easy to install, and very affordable relative to its benefits, making it a small but important component for a worry-free braking experience.
