The thought of an angle grinder is enough to keep many cyclists tossing and turning at night.
There’s no doubt that bike thefts using an angle grinder are on the rise, especially in densely populated urban areas.
This horror has left many cyclists wondering if angle-grinder-proof bike locks have arrived or if we’re still waiting for a hero.
Unfortunately, despite many recent improvements in anti-grinder technology, there isn’t a bike lock on the market that can stop an angle grinder or be considered “grinder proof”.
But don’t let that dishearten you. Several bicycle security brands have been fighting to produce the best anti-grinder bike lock, so there are several excellent options to choose from.
The Best Angle Grinder "Proof" Bike Locks
To save you from searching and scratching your head, the locks below are the top performers in terms of their resistance to angle grinders:
- Altor SAF – Non-portable, but easily the most angle grinder-resistant lock available
- LITELOK X3 – Portable and offers improved grinder protection compared to the Hiplok D1000
- Hiplok D1000 – Incredible grinder resistance, not as resistant as the X3, but will thwart most grinder attacks
- LITELOK X1 – The current cheapest and best option for those in need of a grinder-resistant bike lock
- Skunklock – The original “anti-grinder” bike lock that uses vomit-inducing chemicals to thwart theft attempts
Comparing Angle Ginder Resistant Technology
Until recent years and the surge in popularity of e-bikes, angle grinders weren’t commonly used by bike thieves.
But with an increasing number of highly valuable and easily sellable bikes on our streets, thieves have begun to exploit this situation.
Generally speaking, bike security is like a game of cat and mouse between security brands and bike thieves.
Thieves come up with new ways of defeating the locks, so brands then counter these exploits with design changes.
As shown above, there are currently five different grinder-resistant bike locks. All of these locks use slightly different technologies to achieve their anti-grind properties.
Let’s explore these locks and their tech in a bit more detail:
Altor's Gridner Resistant Tech - ALTOR SAF
The Altor SAF quite literally chews grinder discs apart with its jagged aluminium teeth.
This is the beefiest U-lock on the market and is by no means portable, weighing a whopping 6.2kg (13.7lb).
The SAF’s shackle is 80mm thick and is made from an internal 14mm hardened steel shackle, enveloped by 80mm of barbed aluminium.
Aluminium is surprisingly easy to cut and damage when used, for example, with drinks cans.
However, the internal structure of the Altor SAF’s shackle is specifically designed to snag and tear on grinder disks.
Since aluminium is so malleable, the SAF’s internal structure does a great job of clogging the path of any cutting blades and wearing them out before any real cutting progress is made.
Multiple cuts are required before any of the outer armour can be removed.
Thieves would then have to work their way through to the shackle, which must be cut on either side for a bike to be removed from within.
This isn’t the most advanced anti-grind technology, but it’s an innovative approach, with the SAF taking longer to cut than any other grinder-resistant bike lock.
The Altor SAF hasn’t been submitted for Sold Secure testing, so I asked the Altor team about this.
LITELOK's Anti-Grinder Tech - Barronium
LITELOK took a different approach with their grinder resistance tech than Altor, working with Swansea University School of Engineering to produce Barronium.
Barronium is a ceramic-encrusted composite armour that’s fused to the outside of the LITELOK X1 and LITELOK X3.
When cut with an angle grinder, tiny ceramic particles encased within the Barronium get to work, stripping down the grinder’s cutting disc until it’s rendered useless.
Cutting through the LITELOK X1, which has less Barronium armour than the X3, takes over 2 minutes, even when using a decent cordless grinder.
Considering two cuts are required to compromise both of these anti-grinder locks, thieves are extremely unlikely to be successful in stealing your bike when locked with the X1 or X3.
Most thieves don’t carry replacement grinder discs, but if they do, both of these locks can disintegrate multiple discs before being compromised.
Barronium is seriously impressive, and we’re excited to see what will emerge from the LITELOK lab next.
The X1 and X3 both hold the Pedal Cycle and Motorcycle Diamond rating from Sold Secure – top-tier security.
Hiplok's "Grinder-Proof" Tech - Ferosafe
Ferosafe is the grinder-resistant technology that Hiplok use to produce their D1000 U-Lock.
Ferosafe technology differs from Barronium despite using ceramic particles to fragment and disintegrate grinder discs.
Ferosafe technoloy is owned by Tenmat, a manufacturer and developer of advanced materials. Hiplok buys Ferosafe (from Tenmat), which comes in flat panels. The ferosafe pannels are then welded to the outside of the Hiplok D1000’s hardened steel shackle.
Ferosafe is designed to resist grinder attacks and attacks using carbide-tipped drill bits.
The Hiplok D1000 is slightly quicker to cut than the LITELOK X3 but outperforms the LITELOK X1.
That said, the Hiplok D1000 will shred multiple discs before a thief can remove your bike.
With most thieves carrying a single cutting disc, they’ll be sent home empty-handed if they attempt to cut the D1000.
The Hiplok D1000 received the Sold Secure Pedal Cycle and Motorcycle Diamond rating, making it part of a very exclusive group and one of the most secure locks on the market.
Skunklock's Anti-Grinder Tech - Skunklock
Similar to Altor, the Skunklock team designed the first bike lock ever made with the ability to fight back against thieves.
Instead of shredding grinder discs, the Skunklock hides its grinder-proofing ability inside its shackle.
Inside the shackle is a pressurised hollow compartment, which holds a noxious, vomit-inducing compound.
Regardless of the tool they were using, if a thief attempted to cut through the Skunklock’s shackle, they’d be met with a faceful of naturally occurring fatty acids and, in some countries (where laws allow) capsaicin, an ingredient found within pepper spray.
When inhaled, this joyous cloud will send the unsuspecting thief running in the opposite direction but won’t permanently injure them.
So the Skunklock is a one-time use product, but they sell replacement shackles for cyclists who are victims of theft attempts and subsequently need a new shackle.
The Skunlock hasn’t been rated by Sold Secure, and you can find out why in our detailed review.
Proteus - Yet to Feature on a Bike Lock
Developed by Stefan Szyniszewski, Proteus is another material which offers exceptional anti-grinder properties.
Proteus was recently developed and is currently available for application, with their team working on scaling up production capacity.
Proteus is made from a combination of stiff ceramics bound together by cellular aluminum.
The aluminium makes the material incredibly lightweight, whilst the ceramics shred grinder discs and thwart attacks using carbide drill bits.
We’re still waiting to see Proteus feature on a bike lock, but no doubt, as more bicycle security brands enter the grinder-resistant market, Proteus will be utilised.
So Is There An Angle Grinder Proof Bike Lock?
For anyone who sits at their desk at work, worrying about their bike, which they’ve locked outside, we know your pain too well.
We’d love to sit here and tell you that there’s an uncuttable, anti-grinder bike lock on the way, sadly, at the moment, this isn’t the case.
We can also confidently say that we’ll never see a material with complete cut resistance.
With enough time and the correct tools, any material and locking system can be defeated and cut.
So, whilst all of the locks featured in this article have impressive grinder resistance, none are guaranteed to prevent the theft of your bike.
But in the same breath, it’s highly unlikely that thieves could defeat any of the locks above on the street. So call it what you want!
The Future of Angle Grinder Resistant Bike Locks
We know several grinder-resistance projects that a few other bike security brands are working on.
Some we can talk about, others we will add to this article as soon as we’re allowed to.
The ABUS Super Extreme 2500 is another grinder-resistant bike lock due to be released in 2024.
The Super Extreme 2500 uses a carbide compound to repel angle grinder attacks and has gained the Sold Secure Pedal Cycle Diamond Rating and 4-Star Certification from ART.
So far, we’ve only had grinder-resistant U-locks, so over the next few years, we’re also likely to see other grinder-resistant lock types, such as chains and folding locks (despite being considerably harder to manufacture).
Summary - Is There an Uncuttable Bike Lock?
No. Unfortunately for cyclists, there isn’t a bike lock out there that can be considered uncuttable.
With the correct tools and enough time, any lock can be defeated.
However, as you’ll now understand, locks like the LITELOK X3 and Hiplok D1000 utilise currently unmatched grinder resistance materials.
Barronium (LITELOK) and Ferosafe (Hiplok) are the currently best materials used by bike locks to thwart grinder attacks.
With several more grinder-resistant locks on the horizon, we’ll see increasing competition in this market area, leading to further innovation and refinement of current products.
We’ll keep this article up to date with the release of each new grinder-resistant bike lock or material.
If you want to compare the best grinder-resistant bike locks, read our review.