Bike Lock Showdown 2026: 13 Locks Tested Against an Angle Grinder

Introduction

A bike lock can cost less than a takeaway coffee or more than a second-hand car, and the difference matters when someone with an angle grinder decides to test it. In a head-to-head test, 13 locks were attacked with cutting tools under a strict 10-minute time limit per lock. The lineup ranged from a £6.98 Amazon lock to an £862 heavyweight chain with a 20 mm boron alloy shackle.

The results separate visual deterrents from genuine protection. Some locks lasted seconds, while others survived the full test window. This breakdown covers every lock in the test, what happened, and who should buy each one.

How the Test Worked

Each lock was secured around a bike and attacked with an angle grinder, with a 10-minute time limit per lock. The grinder was intentionally not a high-end tool, and the attack switched to a diamond cutting disc when the locks with special anti-grinder coatings appeared.

Sold Secure ratings also featured throughout the lineup. Sold Secure is an independent testing scheme originally started by insurance companies. It rates locks from Bronze to Diamond: Bronze covers basic protection against less determined thieves, Silver stops opportunists with common hand tools, Gold resists more determined thieves with a wider range of tools and longer attacks, and Diamond survives the toughest tests using powerful specialist tools such as angle grinders.

The results were dramatic. With cheap locks, the grinder barely got warm. With the top-rated locks, 10 minutes of grinding produced little more than a surface mark.

Budget Locks Under £30

The cheap end of the market was brutal. None of these locks should be trusted with anything more than a very short stop in a very safe place.

Sprogut Bike Lock

The Sprogut is an Amazon lock priced at £6.98, and it performed exactly as the price suggests. It was cut in about 14 seconds, so quickly that the angle grinder was barely needed.

The lock looks like a deterrent from a distance, but the metal is thin enough that it offers almost no real resistance.

Sportneer 1999 Bike Lock

The Sportneer 1999 is also from Amazon, and it showed slightly more thought. Its arms lock into place, which means a thief really needs two cuts to get through. In the test it survived about 53 seconds before falling.

That is still a very short time, but the double-cut design does slow things down compared with the cheapest locks.

OnGuard Rottweiler

The OnGuard Rottweiler costs £24.99 and carries a Sold Secure Bronze rating. It looked more serious than the cheap Amazon locks, with a bulky body and a greasy protective coating.

The reality was different. It was cut in around 9 seconds. The coating hides a thin core that offers little resistance against power tools.

Kryptonite Original Keeper

The Kryptonite Original Keeper is another Sold Secure Bronze lock, priced around £30. Despite the trusted brand name, it went the same way as the Rottweiler, cut in about 9 seconds.

As a cheap lock for a low-risk environment it is acceptable, but it will not slow down a thief with a grinder for more than a few seconds.

Mid-Range Locks: The First Real Resistance

This is where the test started to change. Gold and Diamond rated locks began to appear, and cutting times jumped from seconds to minutes.

The jump was dramatic. A lock that survives for almost three minutes forces a thief to work harder, make noise, and attract attention.

Those extra minutes are exactly what matters on the street. The locks below show how the price and rating translate into real resistance.

Kryptonite Evolution

The Kryptonite Evolution is a Gold rated lock at around £50. It took 2 minutes 48 seconds to cut, and part of that delay came from a difficult follow-up cut. That is a strong result for a lock at this price.

That kind of time matters in the real world. It gives a thief a genuine decision to make.

OnGuard 8000 Brute

The OnGuard 8000 Brute costs around £50 and is one of the cheapest Diamond rated locks available. That sounds impressive, but it was cut in about 55 seconds.

The rating reflects a better level of protection than Bronze or Silver, but the test still exposed it as vulnerable to a determined grinder attack.

Hiplok DX

The Hiplok DX is a wearable lock with a Sold Secure Diamond rating, priced at £61.99. It is designed to be worn around the waist, which makes it easy to carry on a ride or commute.

In the test it lasted about 53 seconds, failing only after a fumbled final cut. For a wearable lock the convenience is real, but it is not a grinder-proof option.

OnGuard The Beast

OnGuard The Beast lives up to its name in size. At £84.99 it is a heavy chain lock, although it does not carry a Sold Secure rating.

It took about 1 minute 4 seconds to cut, and the process produced so much heat that the lock actually caught fire during the test. Longer resistance than the cheaper locks, but still well inside the 10-minute window.

The £100 Contender

Kryptonite New York Forget About It

The Kryptonite New York Forget About It is a Diamond rated classic at around £100. In the test it held out for 2 minutes 38 seconds, the hardest cut of the round so far.

The thickness of the steel is what slows the grinder down. It is not grinder-proof, but it forces a serious time investment from any would-be thief.

Angle Grinder Resistant Locks

The final stretch of the test introduced locks with special anti-angle grinder coatings. These changed the game completely.

Instead of clean cuts, the grinder struggled to bite into the surface at all. The softer metal cutting discs disintegrated, and even a diamond disc barely marked the coating.

Both locks below survived the full 10-minute test window with almost no progress made. That is a completely different result from the budget locks at the start of the lineup.

OnGuard Rock Solid

The OnGuard Rock Solid costs £199 and carries a Sold Secure Diamond rating. Its outer coating is designed to stop angle grinder discs from biting into the metal.

In the test, 10 minutes of continuous grinding made almost no progress. The testers were physically drained, with only about 10 percent of the cut completed and hours of grinding estimated to finish the job. This is a genuinely different level of security.

Hiplok DX1000

The Hiplok DX1000 costs £299 and pairs a wearable design with the same anti-angle grinder approach plus a Sold Secure Diamond rating.

It outperformed even the Rock Solid in the test, showing barely a dent after 10 minutes of grinding. The grinder essentially polished the surface rather than cutting through it.

For high-value bikes in high-risk areas, this is the level of protection that makes a thief move on.

What Makes a Lock Grinder Resistant?

Locks in this tier add an outer layer that stops a cutting disc from biting into the steel. In the test, standard metal cutting discs disintegrated against this coating, so the attack switched to a diamond disc normally intended for concrete.

Even then, ten minutes of grinding on the OnGuard Rock Solid produced only a shallow dent, with an estimated hour or more needed to complete the cut. The thicker steel also destroys softer discs quickly, which is one reason these locks demand far more than brute force to defeat.

The Ultimate Test: Squire Behemoth and Stronghold SS100CS

At the top of the lineup sits the £862 Squire Behemoth, a massive chain with a 20 mm diameter hardened boron alloy steel shackle paired with the Stronghold SS100CS padlock, described as the strongest production padlock in the world.

The setup weighs more than all of the other locks in the test combined, and that weight changes how an attack plays out. The chain links are so large that a single cut is not enough; the cuts have to land in the right places or the chain simply stays in place.

The test clocked this setup at 3 minutes 19 seconds, and the process was as much about positioning as raw cutting power.

Squire Behemoth

The Squire Behemoth took 3 minutes 19 seconds to defeat, and the process was as much about positioning as raw cutting power. The huge link size made the cuts surprisingly laborious, despite the chain eventually giving way.

The padlock was not the weak point. The accompanying Stronghold padlock is probably excellent, with the chain being the part that failed first.

Stronghold SS100CS

The Stronghold SS100CS is the padlock supplied with the Squire Behemoth package, built to a standard described as the strongest production padlock in the world.

In the test, the padlock was not the component that failed. Riders who want maximum chain and padlock strength would pair the two, if their budget allows.

Conclusion

The test sends a clear message: cheap locks are visual deterrents, and grinder-resistant locks are the only ones that genuinely stop a determined thief. Sold Secure ratings help, but the actual steel between the grinder and your bike matters more than the label on the box.

Buy the best lock you can carry and afford, and match it to the value of the bike and the risk of the location. The extra minutes a good lock buys could be the difference between coming back to your bike and walking home.