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6 Uncuttable & Unbreakable Bike Locks

five unbreakable bike locks

With the ever-increasing number of high-tech bicycles and bike components on the market, the need for uncuttable & unbreakable bike locks is at an all-time high. 

If you’re a cycling enthusiast and wince at the thought of someone stealing your pride and joy, you’ve come to the right place. 

In this short article, you’ll learn about the six highest-security uncuttable & unbreakable bike locks available to buy. 

Is there such thing as a bike lock that cannot be cut, or is this a fairy tale fantasy? Let’s find out. 

Table of Contents
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    Early Insight

    So before we get into the nitty-gritty, I wanted to make it 100% clear to you, as it stands, with the right tools and enough time, any bike lock can be cut or broken.

    Fortunately, the six locks featured in this review implement ingenious features which make them the most uncuttable locks on the market.

    I own and have used every lock featured in this review. Over the last few weeks, I’ve tested out over 15 locks and have narrowed it down to the 6 strongest locks below. 

    The 6 Best Uncuttable & Unbreakable Bike Locks


    The Best Grinder-Resistant Lock to Date

    LITELOK X1 Bike D Lock Review



    Check Price:

    LITELOK X1 Specifications:

    Security Rating – Sold Secure Diamond (Bicycle & Motorcycle)
    Weight – 1.7kg (3.75lb)
    Shackle Dimensions – 10 x 19.2cm (3.94 x 7.56″)
    Shackle Thickness – 17mm Fine Grain Hardened Steel
    Warranty – 3 Years

    The LITELOK X1 is the latest lock on the market that renders angle grinders useless and easily earns its place amongst the best uncuttable & unbreakable locks.

    I attended the LITELOK X launch event and was blown away by the capabilities of the X1 compared to several “top of the range” D locks. 

    Whilst the LITELOK X1 resembles your average D lock, don’t let this fool you. The X1 raises the standards for security within the bicycle security industry, and other brands will be jealous of LITELOK’s accomplishment.

    Barronium, LITELOK’s innovative, anti-grinder ceramic technology, is fused to the outside of the X1’s 16mm hardened steel shackle. So what’s Barronium, you ask?

    The outer ridges fused to the X1’s shackle are its anti-grinder Barronium armour. The armour brings the total thickness of the X1 to 17mm, rendering even the largest bolt cutters useless.

    Barronium is a highly cut-resistant ceramic compound which acts as an exoskeleton for the X1.

    If a thief attempts to cut the X1 with an angle grinder, tiny ceramic fragments within the Barronium armour are released, quickly turning the cutting disc on itself until it’s rendered useless. 

    Several guests and I got the opportunity to put the X1 to the ultimate test at the launch event. Needless to say, many cutting discs were destroyed before a successful cut was made through the X1’s shackle. 

    At 1.72kg (3.79lb) the LITELOK X1 is significantly lighter than the Kryptonite Fahgettaboudit Mini which weighs 2.04kg (4.50lb) and provides hugely increased resistance against all cutting attacks. 

    After watching many others fail hopelessly, I managed a single cut through the X1’s shackle in 1 minute and 57 seconds.

    To put this into perspective, we made a single cut through the Kryptonite Fahgettaboudit Mini’s shackle in 15 seconds. 

    Fortunately, both locks feature dual-locking anti-rotation shackles, meaning two cuts are required for a bike to be removed from inside the shackle.

    And whilst our cutting times were carried out in lab conditions, the performance of the X1 compared to the Fahgettaboudit Mini is startling. 

    LITELOK X1 Shackle after angle grinder testing
    Three attempts to cut the X1's shackle and three cutting discs disintegrated.

    The only lock that comes close to the LITELOK X1 is the Hiplok D1000, which is significantly more expensive and heavier to carry. 

    If you worry about the security of your bike whilst you’re away from it, there isn’t a better portable all-round lock than the X1. 

    This is the lock that I’m using moving forwards, and for its competitive price [LITELOK website], it’s a no-brainer to use the X1 with e-bikes and other high-value bicycles.  

    If you’re interested in the X1, first of all, I don’t blame you. Secondly, you should read my in-depth review of the LITELOK X1.

    Altor SAF Lock (Strong As F***)

    An Angle Grinder & Bolt Cutter Proof Monster Lock

    ALTOR SAF Bike lock locked to high value bike
    Worry about your bike all day long? Not with the SAF Lock



    Check Price:

    Product Discontinued (Nov 2023)

    Altor SAF Specifications:

    Security Rating – Not Rated
    Weight – 6.2kg (13.7lb)
    Shackle Dimensions – 8 x 14cm (3.15 x 5.5″)
    Shackle Thickness – 80mm Aluminum & Hardened Steel
    Warranty – 1 Year

    Altor have taken bicycle security to a whole new level. As I covered above, any bike lock can be defeated with the right tools and enough time, apart from the Altor SAF.

    The SAF lock is a D lock (U lock) on steroids. If you’re looking for a bike lock that can’t be cut with an angle grinder, this is one of the very few. 

    Altor claim this is the first “angle grinder proof bike lock”, and essentially, it is. Dan Roe from Bicycling was the first YouTuber to put this uncuttable lock to the test against an angle grinder.

    Triumphant he was, defeating the SAF was no easy feat. You’ll want to watch the video below.

    After the 1-hour 40-minute battle, Dan had exhausted six batteries, four blades, and two angle grinders. Finally, the Altor SAF was defeated.

    All jokes aside, this experiment highlights the expertise and innovative minds behind the design of the Altor SAF. 

    Any lock that holds out for nearly two hours against power tools deserves recognition and is virtually unbreakable and uncuttable. 

    I’ve got my own Altor SAF which I’ve used with my high-value bikes. Let me tell you, there isn’t a lock out there that fills me with more confidence than the SAF lock. 

    At 80mm thick the SaF lock is uncuttable with bolt cutters and its soft aluminium shell makes it unbreakable with an angle grinder

    The only setback for the SAF is that it’s not suitable for use on the go. Weighing 13.7lb (6.2kg), this lock is a stationary bike lock, whereas the LITELOK X1 (above) can easily be carried whilst riding. 

    For commuters who want unrivalled protection, leave the SAF locked at work, this way, you’ll have unrivalled security waiting for you at work each day.

    But then what will you use to lock your bike at home? Fortunately, Altor offer pairs of SAF locks at a discount, they’re also operated using one set of keys. These locks are pricey, but so is replacing a stolen bike!

    Despite how impressive this lock is, after speaking with Dylan Cato, Co-founder of Altor, he let me know that the SAF has been discontinued as of November 2023. 

    This is a lock that will go down in the history books, so if you are interested, you should read our detailed review of the Altor SAF lock


    The Ingenious Vomit-Inducing Bike Lock

    Skunklock Uncuttable Bike Lock



    Skunklock Specifications:

    Security Rating – Not Rated
    Weight – 1.78kg (3.91lb)
    Shackle Dimensions – 10.8 x 22.94cm (4.25 x 9.01″)
    Shackle Thickness – 19mm Hardened Steel & Hollow
    Warranty – 30 days

    The third lock in our list of uncuttable bike locks is the Skunklock, and just like a skunk, you wouldn’t want to be nearby when this thing goes off. 

    Yep, that’s right, this is the first lock I’ve come across with the ability to fight back against thieves. 

    The Skunklock uses patented technology to house a pressurised vomit-inducing compound inside its 19mm shackle. 

    An outer 8mm layer of hardened steel protects the internals that suspends the pressurised compound inside the Skunklock. 

    Unlike the Altor SAF the Skunklock only weighs 3.91lb (1.78kg) making it an uncuttable lock, suitable for use on the go

    If a thief ignored the warnings clearly printed on the Skunklock and cut through its outer layer, they’d soon wish they hadn’t.

    The pressurised vomit educing compound will quickly de-pressurise in the local vicinity. 

    The following moments won’t’ be forgotten by the thief, and whilst this sounds slightly barbaric:

    Not a smell that thieves will enjoy, hehehe...

    1. The chemicals used are food-grade and not designed to cause any permanent harm

    2. The Skunklock has been designed to be legal in most states and countries

    3. The thief is attempting to steal your bike….

    How to lock your bike with the Skunklock
    Unlike the Altor SAF the Skunklock is capable of locking both of your bike's wheels and its frame!

    The ability to fight back against thieves makes the Skunklock one of four locks I know of with the ability to defeat an angle grinder.

    This secured its place amongst the best unbreakable and uncuttable bike locks on the market.

    The Skunklock’s 19mm shackle is also too thick to be cropped by hand, making this another bike lock that can’t be cut with bolt cutters.

    Interested in this portable uncuttable lock? Read my in-depth review here. Otherwise, you can view the most up-to-date price for the Skunklock on the Amazon website.

    Pragmasis Protector Chain

    Top of the Range Chain, Unrivalled Quality

    Pragmasis Protector 16mm Uncuttable Bike Lock Chain



    Protector Specifications:

    Security Rating – Sold Secure Pedal Cycle Diamond & Powered Cycle Gold
    Weight – 4.9kg (9.92lb) Per Meter
    Chain Length – 0.8 – 6m (Customisable)
    Link Thickness – 16mm Hardened Steel
    Warranty – 2 Years

    The Pragmasis Protector Chains are by far the best bike chains I’ve reviewed. 

    Compared to the Skunklock, Altor SAF and LITELOK X1, these chains keep it simple. But believe me, cutting through the protector chain would be anything but simple. 

    The Protector chains are available in multiple different sizes. For those of you looking for a “cut-proof bike chain”, the 16mm chain is guaranteed to be, in Pragmasis’ words, “uncroppable” and “guaranteed impossible to bolt-crop by hand”. 

    The protector range includes several of the most unbreakable bike chain locks on the market.

    The Protector Chain works with a wide range of padlocks and D locks and can be ordered with a regular or noose end link. The noose end is ideal for locking multiple bikes.

    If 16mm of Hardened Boron Steel isn’t quite cutting it for you (pun not intended), then maybe the 19mm Protector Chain will suffice? 

    Still not quite unbreakable enough for you? Then you’ll want to get hold of the 22mm Protector Titan chain lock. This is a chain that means business. 

    To put it into perspective for you, the Titan’s 22mm chain links weigh approximately 1.8lb (0.8kg) each, which’s the same weight as many lightweight bike locks!

    Pragmasis Protector 16mm
    The 16mm Protector Chain's Links weigh 1lb (0.45kg) each meaning the 4.9' (1.5m) chain weighs 14.7lb (6.68kg)

    The largest hand-powered bolt cutters out there (Irwin Record 924s) won’t physically open wide to encompass the 16mm chain, let alone the 22mm Titan links.

    All we need now is for Skunklock and Pragmasis to do a chain lock collab, and we’d have a truly uncuttable, unbreakable bike chain lock. 

    Different locks are sold with these chains; you can find them on the Pragmasis website. Otherwise, you can view the most up to date prices on Amazon for each model by following the links below.

    16mm Protector Chain [Amazon]

    19mm Protector Chain [Amazon]

    22mm Protector Titan Chain [Amazon]

    If you decide on the 19 or 22mm chains, due to their weight, you’ll need to take considerable care when using them to lock your bike.

    These unbreakable bike locks are no joke, if you’re not careful, they could damage your bike. 

    Oxford Alarm-D Pro

    120dB Anti-Theft Alarm Prevents Prolonged Attacks

    Oxford Alarm D pro uncuttable bike lock



    Check Price:

    Alarm-D Pro Specifications:

    Security Rating – Sold Secure Pedal Cycle Gold
    Weight – 1.48kg (3.26lb)
    Shackle Dimensions – 9.88 x 20cm (3.89 x 7.87″)
    Shackle Thickness – 14mm Hardened Steel
    Warranty – 2 Years

    Similarly to the Skunklock, the Oxford Alarm-D Pro uses a powerful deterrent that will send thieves running.

    Before we get to the in-depth details, the Oxford Alarm-D Pro is, in theory, the easiest lock to cut in this list. But it’s also the most affordable by far and achieved the Sold Secure Gold rating.

    So what makes this an uncuttable bike lock, you ask?

    The combination of its 120dB ear-piercing anti-theft alarm and 14mm hardened steel shackle.

    Thief scared by bike lock with alarm
    Anyone disturbing the Alarm-D Pro will soon wish they hadn't!

    This smart bike lock uses highly sensitive 3d motion sensors. If motion is detected, a loud warning tone will sound for 5 seconds. If that isn’t enough to prevent further interference, the 120dB alarm will begin to blast.

    The alarm is easily loud enough to be an effective deterrent on its own and will likely attract attention from passers-by, alerting them to what’s going on. 

    According to the American Academy of Audiology, 120dB is the same noise level as a jet plane during take-off. They also state that exposure to this level of sound for over 30 seconds is dangerous. 

    When I reviewed this lock for the first time, I foolishly set it off indoors. Let me tell you now, I won’t be rushing to do it again!

    Apart from the alarm feature, the Alarm-D Pro uses a 14mm hardened steel shackle. This isn’t quite thick enough to be considered “uncuttable”, but the 120dB alarm feature will deter most thieves.

    As well as being one of the top unbreakable bike locks, the Alarm-D Pro is also the best bike lock with alarm.

    But as you’ll see in the video above, if the lock senses any disturbances, it won’t hesitate to set off its piercing alarm.  

    The Alarm-D Pro isn’t as unbreakable as the other locks in the list, but I wanted to include a more affordable option for those on a tighter budget.

    This lock is also highly portable and is supplied with an effective mounting system for easy transportation. 

    If you’d like to find out more about this lock, have a read of my in-depth review. Otherwise,  you can check the most up to date price for the Alarm-D Pro here [Amazon].

    Kryptonite New York Fahgettaboudit Mini

    Defeats All Hand Powered Bolt Cutters & Remains Portable

    Kryptonite Fahgettaboudit Uncroppable Bike Lock



    Fahgettaboudit Specifications:

    Security Rating – Sold Secure Pedal Cycle Diamond
    Weight – 2.02kg (4.49lb)
    Shackle Dimensions – 8.3 x 15.3cm (3.25 x 6″)
    Shackle Thickness – 18mm Hardened Steel
    Warranty – Lifetime

    Last but not least, we have the lock I refer to as my Ol’faithful, as this was my lock of choice for years, before my recent upgrade to the LITELOK X1.

    Kryptonite’s New York Fahgettaboudit Mini has an interesting story behind its name.

    In 1989, several years after Kryptonite introduced their Anti-Theft Protection Offer (ATPO), they became aware that one area was racking up way more ATPO claims than anywhere else. 

    You guessed it, New York. Unfortunately, this huge influx of claims led to Kryptonite having to suspend the offer to New York residents in 1989.

    Instead of tapping out there accepting defeat, Kryptonite had their lead engineers meet this issue head-on, and in 1994, they reinstated the offer and released the New York Fahgettaboudit Lock

    To this day, the Fahgettaboudit has remained their best and most secure option.

    The shackle of this D lock uses 18mm of Max-Performance Hardened Steel to protect your bike. Making this yet another lock that’s uncuttable with bolt cutters and virtually unbreakable with any hand-powered tool. 

    Unlike some other locks in this review, the Kryptonite Fahgettaboudit is compact and portable.

    Because the Fahgettaboudit is “Mini” it will comfortably fit into your rucksack, making it a great option for those who commute to work by bike. 

    In reality, the Fahgettaboudit could be cut with an angle grinder without releasing vomit-inducing gasses, and it doesn’t have a 120dB alarm feature. 

    However, due to its hardened double deadbolt, at least two cuts have to be made (one on either side of the shackle) before this lock will budge.

    In a controlled, lab environment a single cut through the Fahgettaboudit shackle took 15 seconds. 

    Mount for kryptonite fahgettaboudit mini

    Bear in mind during testing the Mini was cut in a vice, and on the street, it’d take considerably longer as it’d be difficult to hold the lock still. 

    The Fahgettaboudit Is one of the cheaper locks in this review and is more affordable than the LITELOK X1. So, if you’re on a budget and want a portable, bolt-cutter-proof bike lock, this is it. Read my in-depth review here.

    Otherwise can find the most competitive price for the Fahgettaboudit here [Amazon].

    Or read my in-depth review of the Fahgettaboudit Mini here.

    Uncuttable & Unbreakable Bike Lock FAQ's

    Technically speaking there isn’t a bike lock on the market that’s unbreakable. With the right tools and enough time, any lock out there could be cut or broken. 

    The locks featured in this article review are the most uncuttable locks on the market. All six locks use different deterrents to increase the security of your bike and prevent theft. 

    Unfortunately there isn’t a lock out there that can’t be cut. 

    That being said, the Kryptonite Fahgettaboudit Mini’s 18mm hardened steel shackle is impossible to crop by hand with bolt cutters. 

    So if you were looking for a bolt cutter proof bike lock, check the Fahgettaboudit out in the review above.

    If a thief were to use the right tools and had enough time, unfortunately there isn’t a single lock on the market that they couldn’t cut through. 

    The ABUS Granit Extreme 59 is their most secure U lock to-date and its 16mm square parabolic shackle makes light work of even the biggest bolt cutters. 

    However, unlike the LITELOK X1 or the Hiplok D1000, the ABUS Extreme 59 doesn’t have any anti-grinder technology so remains vulnerable to power-tools.  

    Without a doubt, the Altor SAF is the toughest bike lock on the market.

    Its shackle is 2.36″ (6cm) thick at its narrowest point, making it impossible to cut with bolt cutters and it took over 1 hour 40 minutes to defeat the SAF Lock with an angle grinder.

    The Altor SAF, LITELOK X1 and the Hiplok D1000 are the three most uncuttable bike locks on the market. 

    All of these locks employ anti-grinder and anti-cut features that give them power tool-defeating capabilities.

    These three locks are the strongest and most unbreakable bike locks on the market by quite some distance.

    Summary - Uncuttable Bike Locks

    And… that’s about as far as uncuttable & breakable bike locks go.

    As new ultra-high security locks are released I’ll be updating this article, so that you can guarantee these are the strongest and most unbreakable locks out there. 

    Due to the influx of high-end e-bikes, you can guarantee we will start to see more uncuttable locks popping out of the woodwork over the next few years.

    We recently published a piece on Anti-Grinder Bike Lock Technology; if you’d like to learn more about the most recent advances, have a read!

    Otherwise, if the locks in this review are out of your budget or you’re simply looking for some other ideas, why not check out my review of the best bike locks or the best cheap bike locks?

    Recent Updates:

    Author of This Post:
    Picture of James Grear (Lead Editor)
    James Grear (Lead Editor)

    Understanding how devastating it is to have a bike stolen, I've researched & immersed myself in the world of bicycle security since 2013.

    I then built BikeLockWiki in 2019 to share everything I'd learned with the worldwide cycling community so that cyclists can improve their bike security skills and make informed decisions when purchasing new products and services.

    Learn More about Me & BikeLockWiki here.

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