Okay, so I’ve been rocking this OnGuard RockSolid U-lock for a few months now, and let me tell you—it’s a beast. First off, that angle grinder-resistant coating? Legit. I haven’t had anyone try to steal my bike (thankfully), but knowing it can stand up to power tools gives me serious peace of mind.

The X4P locking mechanism is smooth but tough. Four locking points mean no easy prying or jacking. The shackle is thick (14mm, but feels like 15mm with the coating), and the rubber sleeve adds extra bulk—kinda makes it look intimidating, which I love.

It’s lighter than my old Kryptonite lock (by like 1.5 lbs!), so carrying it around isn’t a chore. No bike mount included, but I just toss it in my bag or clip it to my rack. The keys are solid—five of them!—though I wish one had a light for those late-night rides.

Only gripe? The interior space is *slightly* smaller than advertised (83mm x 174mm vs. 90 x 175mm). Fitting it around thicker frames or immovable objects can be tight. Also, the Quattro mechanism isn’t totally rattle-free—minor wiggle, but nothing deal-breaking.

Overall? If you want a lock that balances weight, security, and grinders-be-damned toughness, this is it. Pair it with a secondary lock for max protection, and sleep easy knowing your ride’s safe.