BikeLockWiki is reader-supported. When you buy through links on my site, I may earn an affiliate commission.

5 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 five 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
    Add a header to begin generating the table of contents

    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 five 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 5 strongest locks below. 

    Top 3 Unbreakable & Uncuttable Locks

    Preview
    Most Secure
    Portable & Uncuttable
    Model
    Altor SAF Lock
    Pragmasis Protector 16mm
    Skunklock
    Pros
    • Uncuttable with angle grinders
    • Strongest D Lock ever made
    • Uncuttable with bolt cutters
    • Strongest bike chains
    • Thwarts all forms of attack
    • Suitable for using on the go
    Cons
    • Not portable like the Skunklock
    • More vulnerable to angle grinders
    • Not as strong as the Altor SAF
    Bottom Line
    At 85mm thick, this lock is definitely uncuttable. If you want the most secure lock possible this is it.
    One of the best bike chain locks money can buy. If you need to lock multiple bikes, this is a great unbreakable option.
    This is not a lock to be messed with. If anyone gives it a go they'll soon regret it. Uncuttable than to its skunk defence system.
    Most Secure
    Preview
    Model
    Altor SAF Lock
    Pros
    • Uncuttable with angle grinders
    • Strongest D Lock ever made
    Cons
    • Not portable like the Skunklock
    Bottom Line
    At 85mm thick, this lock is definitely uncuttable. If you want the most secure lock possible this is it.
    Preview
    Model
    Pragmasis Protector 16mm
    Pros
    • Uncuttable with bolt cutters
    • Strongest bike chains
    Cons
    • More vulnerable to angle grinders
    Bottom Line
    One of the best bike chain locks money can buy. If you need to lock multiple bikes, this is a great unbreakable option.
    Portable & Uncuttable
    Preview
    Model
    Skunklock
    Pros
    • Thwarts all forms of attack
    • Suitable for using on the go
    Cons
    • Not as strong as the Altor SAF
    Bottom Line
    This is not a lock to be messed with. If anyone gives it a go they'll soon regret it. Uncuttable than to its skunk defence system.

    Last update on 2021-09-27 at 11:38 / Affiliate links / Images from Amazon Product Advertising API

    The 5 Best Uncuttable & Unbreakable Bike Locks

    Altor SAF Lock (Strong As F***)

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

    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, although 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. 

    Unbreakable bike 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.

    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!

    Because the SAF Lock has been so popular since release it’s often out of stock. However, you can view the best price and most up to date stock for the Altor SAF lock here [Amazon].

    Skunk Lock

    The second 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. 

    How much does the skunklock bike lock weigh
    Skunklock shackle width

    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:

    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 two locks I know of with the ability to defeat angle grinder. This secured its place amongst the best unbreakable and uncuttable bike locks on the market.

    Its 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 here on their website.

    Pragmasis Protector Chain

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

    Compared to the Skunklock and Altor SAF, 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”. 

    Essentially these are 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 a small D lock!

    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 

    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? It’s 120dB ear-piercing anti-theft alarm and 14mm hardened steel shackle.

    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.

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

    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.

    Oxford Alarm-D Pro Uncuttable Bike Lock
    Oxford Alarm-D Pro Bike Lock Weight

    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

    Last but not least, we have the lock I refer to as my Ol’faithful. 

    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 hand-powered tools. 

    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.

    Because of the increased time it takes to cut this lock, it’s likely that thieves will attract attention to themselves from passers-by or give up and move onto an easier target.

    Mount for kryptonite fahgettaboudit mini

    The Fahgettaboudit Is also one of the cheaper locks in this review. 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].

    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 five 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.

    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 and the Skunklock are the two most uncuttable bike locks on the market. 

    Both of these locks employ anti-cut features that make them capable of defeating power tools. These two locks are the strongest and most unbreakable bike locks on the market. 

    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.

    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?

    Recommended Posts
    Follow BikeLockWiki:
    Affiliate Disclosure

    As an Amazon Associate I earn from qualifying purchases. Read More…

    Brands We've Worked With
    About Me
    Me and My Bike

    Hello! My name’s James, I’m an avid cyclist and the lead editor of BikeLockWiki.

    I’ve invested over four years into researching & studying bicycle security. Now I want to share the information I’ve learnt, for free, with the online cycling community.

    Trending Posts