Cassette lockrings and certain disc brake lockrings share the same 12-spline interface, which means the tool you reach for most often needs to handle both jobs without a second thought. Park Tool's FR-5.2 Cassette Lockring Tool fits that 12-spline, 23.4mm diameter pattern used across Shimano, SRAM (including 1x), SunRace, SunTour, and Chris King cassette lockrings from 7- through 12-speed drivetrains. The same splined head also engages Shimano disc brake rotor lockrings and lockring adapters with 12 internal splines, plus the top caps on select RockShox suspension fork models including Pike, Lyrik, SID, Revelation, Reba, and Paragon.

The FR-5.2 replaces the older FR-5 with deeper splines that engage a wider range of lockring profiles. If you had an original FR-5 that wouldn't quite seat into certain disc brake lockrings, this is the updated version that addresses that gap. The thin wall construction clears cones and locknuts on traditional hubs, so you can get the tool seated without disassembling the axle hardware first. A 12mm center bore provides clearance for thru-axle hubs without interference.

One thing to keep in mind: the FR-5.2 is the splined fitting only. You'll need a 1" wrench, adjustable wrench, or 1" socket to actually drive it. The hexagonal base accepts any of those, and it also clamps into a bench vise if you prefer to turn the wheel rather than the tool. For cassette removal, you'll also need a chain whip to hold the cogs still while you break the lockring free. This is not a Campagnolo tool — if you're working on a Campagnolo cassette, you need the BBT-5/FR-11 instead.... Read More