OnGuard RockSolid
Strongest U-lock against angle grinders, low weight and excellent value.
Consolidated from 15 cited sources across 12 outlets
Where the cited sources landed, as we read them
- 1 enthusiastic source
- 12 positive sources
- 2 mixed sources
Pros & cons
- ✓ Best overall choice for angle-grinder resistance
- ✓ Lightweight compared to other high-security U-locks
- ✓ Exceptional value for the price
- ✓ Top pick for grinder resistance
- ✓ Lightweight design
The sources behind this ranking
We searched the web and YouTube for what has been published about this product, then read the articles, video transcripts and comments we found.
Evidence 11 articles and 4 video reviews
12 positive sources
WIRED Ryan Waniata · reviewer · Oct 2020 RockSolid stood up to a slew of informal angle-grinder tests we've reviewed by other testers, in many cases besting U-locks with the more stringent Powered Diamond rating reserved for motorcycle and ebike locks. The RockSolid is also secured at four points within the shackle, meaning thieves would have to cut through both sides of the lock to get clear of it.Read T
The Sweet Cyclists The Sweet Cyclists · 18.4K subscribers · Oct 2024 OnGuard’s new RockSolid 8590 U‑lock is one of the lightest angle‑grinder resistant locks on the market that provide maximum protection without extra bulk.Watch C
Cycling Weekly Article · Oct 2022 As I mentioned, there are various styles of bike locks, but our best overall choice is the OnGuard RockSolid for its resistance to angle grinders, low weight, and exceptional value. Because there is such a wide range of options, there are tips for selecting the right one for you in our How To Choose section at the bottom of this page.Read T
The Best Bike Lock The Best Bike Lock · 1.2K subscribers · May 2025 I tested the OnGuard RockSolid against an angle grinder with impressive results. This lock puts some of the others to shame!Watch C
Cycling Electric mark sutton, Geoff Waugh · reviewer · Aug 2026 Still, that is no different to the other locks in this test, but what did come as a surprise was the RockSolid’s defence in the angle grinder test. While the rubber cover was quickly sliced though, as soon as the blade hit the metal the dimpled surface texture resisted any purchase or bite point.Read E
Extra UK Extra UK · 829 subscribers · Jul 2024 The new OnGuard RockSolid weighs a tiny 1.4kg, and yet protects bicycles and powered bikes from sustained and repeated angle grinder attacks, to keep your pride and joy safe.Watch C
Cycling Weekly Article · Feb 2025 Proving to be virtually impenetrable, affordable, light, and small enough to fit in your pocket, it's no wonder that the OnGuard RockSolid 8590 bike lock was voted the best overall.Read D
DedieMoon DedieMoon · 226 subscribers · Feb 2026 Angle Grinder Resistant Design: Engineered with OnGuard’s proprietary RockSolid coating that resists angle grinder attacks, offering elite-level protection in high-risk urban environments for cyclists and commuters.Watch E
E-Catalog Article The OnGuard RockSolid - The World’s Lightest Angle Grinder Resistant D LockRead C
Cyclingnews Article · Dec 2025 one of the best around is the OnGuard RockSolid U‑LockRead P
ProCyclingUK Mathew Mitchell · reviewer · Mar 2026 Dimpled shackle denied the grinder any gripRead C
Cyclist Cyclist magazine · reviewer · Jul 2026 Our pick of the best bike locksRead
Frequently asked questions
It ranks #2 of 15 on our bike locks tier list, in A tier. That placement draws on 15 cited sources across 12 outlets.
The OnGuard RockSolid is for the rider whose main worry is a thief with an angle grinder. Reviewers call it the strongest U-lock against grinders on our board, and it does that at a low weight and a price they describe as exceptional value. It sits in A tier, second only to the Litelok X1. If grinder attacks are not common where you park, the Litelok X1 gives you high security for less.
It resists one better than any other U-lock on our board. Reviewers name the OnGuard RockSolid their top pick for grinder resistance. No lock is grinder-proof, so what you are buying is time, noise and spent discs, which is usually enough to send a thief to an easier target. Compare that with the Kryptonite New York U-Lock, which reviewers cut with a handheld grinder in under a minute.
They are listed separately on our board because reviewers tested them separately. The OnGuard RockSolid 8590 is a specific model number in the RockSolid line, and it also sits in A tier on strong video-tested resistance to common attacks. The OnGuard RockSolid entry ranks one place higher on grinder resistance, weight and value. If you are choosing between them, either is a sound A tier buy and the 8590 is the one to search for by model number.
No, not for what it resists. Reviewers single out the OnGuard RockSolid as lightweight compared with other high-security U-locks. Grinder-resistant locks usually pay for their resistance in weight, so this is the reason it ranks where it does. Carry it in a frame mount or a pannier rather than a jersey pocket.
Put the shackle through the frame and the rear wheel and around a fixed object that cannot be lifted or cut. Fill the shackle so there is no room to fit a jack or lever, keep it off the ground and point the keyway down. A second lock of a different type for the front wheel makes a thief carry two tools.
Ranked nearby in Bike Locks
S tier #1 Litelok X1
A tier #3 OnGuard RockSolid 8590
B tier #4 Abus Granit Super Extreme
B tier #5 Abus Bordo Granit
B tier #6 1 of 5 research runs entered this as a product to avoid rather than a pick. Abus Granit Super Extreme 2500
C tier #7 1 of 6 research runs entered this as a product to avoid rather than a pick. Hiplok DX1000
D tier #12 2 of 6 research runs entered this as a product to avoid rather than a pick. OnGuard 8020 Mastiff
D tier #13 4 of 7 research runs entered this as a product to avoid rather than a pick. Kryptonite Evolution Mini-7
D tier #14 3 of 6 research runs entered this as a product to avoid rather than a pick. Hiplok DXF
F tier #15 2 of 6 research runs entered this as a product to avoid rather than a pick.