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OnGuard Mastiff Review – The Best Budget Bike Chain Lock?

7 min read

After reviewing the OnGuard Brute & Pitbull D/U Locks, I was curious as to how OnGuard’s chain locks would compare.

I reached out to OnGuard who were very keen for me to produce an OnGuard Mastiff Chain Review.

The OnGuard Mastiff range is made up of five different bike chain locks. They manufacture two mastiff chains with integrated locks, one with a rotary padlock and two that are secured with the Boxer U-Lock.

The Mastiff 8019 is one of the two chains that use the Boxer U-Lock, a lock that I hadn’t had experience with before producing this review.

OnGuard Mastiff 8019 bike chain lock review

OnGuard are known for the high-quality locks they manufacture and the budget price they’re sold at. I’ve been excited to review the Mastiff 8019 for a while now!

Throughout this review, I’ll breakdown the Mastiff 8019’s strengths and weaknesses as well as comparing it to some similar bike chain locks.

First, let’s take a look at the security this chunky chain lock offers.

Table of Contents
    Add a header to begin generating the table of contents

    Overview - OnGuard Mastiff 8019 Review

    The OnGuard Mastiff 8109 is a Sold Secure Gold rated bicycle chain lock. Weighing 6.94lb (3.15kg), it’s relatively lightweight for a chain of its length (42″ (106cm)) and offers a wide range of locking options for its users.

    The Mastiff’s 10mm titanium hardened chain links make it resistant to all forms of attack including drilling, sawing and hammering.

    This being said it’s worth noting that 10mm isn’t thick enough to be considered bolt cutter proof.

    The OnGuard Boxer D/U lock secures either end of the Mastiff chain. The Boxer’s 14mm hardened steel shackle ensures that the locking mechanism doesn’t provide a targetable weak point for thieves.

    Whilst reviewing the Mastiff 8019, I didn’t experience any issues, OnGuard’s locks tend to be a bit stiffer to begin with, but loosen up quickly when used.

    Nothing you wouldn’t expect to find from such an affordable chain lock.

    If you want to view the most up to date and competitive price, you can find the Mastiff on Amazon here.

    OnGuard Mastiff 8019 Specs
    Weight: 6.94lb (3.15kg)
    Length: 42" (106cm)
    Link Diameter & Material: 10mm Titanium Hardened Steel
    Sold Secure Rating: Sold Secure Gold

    How Secure Is the OnGuard Mastiff 8019?

    So as I’ve just covered, the Mastiff 8019 is made up from the Mastiff chain and OnGuard’s Boxer U-Lock. The Mastiff 8019 was awarded the Sold Secure Gold rating and was rated 92/100 by OnGuard on their in-house security scale.

    OnGuard Mastiff 8019 Sold Secure Gold

    These security ratings mean the Mastiff offers security comparable with some of the most secure chains on the market.

    Let’s find out just how secure this chain lock is and how it would stand up against a determined thief.

    How Secure is The Mastiff 8019's Chain?

    The OnGuard Mastiff 8019 uses a 42″ (106cm) long titanium hardened steel chain. This chain is made up of multiple 10mm hexagonal links.

    Hexagonal links present more surface area than a standard round chain link which make cutting and sawing through the Mastiff chain extremely difficult.

    It’s worth noting that whilst the Mastiff is an exceptionally robust chain lock, its 10mm links could be cropped by the largest bolt cutters. That being said it wouldn’t be easy to cut by hand.

    OnGuard Mastiff chain & Boxer D/U lock

    The largest bolt croppers are hard for thieves to conceal in public, so they tend to opt for smaller portable cutters. These would struggle to break through the Mastiff’s titanium hardened 10mm links.

    You should also remember that no bike lock is unbreakable. That being said, there are several methods of locking that you can learn to significantly reduce your bike’s vulnerability whilst it’s secured. I’ll cover these later on in the review.

    How Secure is the Mastiff 8019's Lock?

    OnGuard’s Boxer 8084 U-Lock is the locking system used to secure either end of the Mastiff chain. This mini D/U Lock is essentially a miniature version of the OnGuard Pitbull, a bike lock which rightfully earned its place amongst the best cheap bike locks.

    OnGuard Boxer vs Pitbull

    The Boxer U-Lock uses a 14mm hardened steel shackle, which is resistant to all forms of attack. Again, 14mm isn’t thick enough to be considered bolt cutter proof, but cutting through the Boxer would not be straightforward.

    (Click to enlarge)

    Thanks to the Boxer’s X4P quad bolted locking mechanism, two complete cuts would have to be made through the 14mm shackle before a thief could remove the Mastiff chain.

    Quad bolted shackles offer more security than a single bolted locks. Single bolted mechanisms are generally found on cheaper low-end bike locks.

    Because the Boxer U-Lock uses a small 2.17″ x 2.17″ (5.5cm x 5.5cm) shackle it also makes it much more resistant to twist & hydraulic attacks.

    Cheap bike lock
    This cheap D/U lock had its shackle twisted open, a single bolted shackle that's this thin would only take seconds to pop open.

    A single bolted bike lock would only need one cut through its shackle for your bike to be stolen. Which means the OnGuard Mastiff 8019 offers increased levels of protection for your bike.

    How Practical is the OnGuard Mastiff 8019?

    Weight and Size

    Weighing 6.94lb (3.15kg) the Mastiff is a very reasonable weight for a chain of its size and for the security it offers.

    It didn’t cause me any discomfort when I went for a ride with the Mastiff over my shoulder, and It wouldn’t be too heavy for everyday use.

    Compared to other chains of its size, the Mastiff 8019 is relatively lightweight.

    If you commute to work by bike, you’d be better off storing this chain in a backpack. I had no issues fitting the Mastiff 8019 into my bag.

    Understandably, a 42″ (106cm) chain lock requires more room in a backpack than any D/U Lock. Still, you’ll have more locking options available to you when securing your bike.

    OnGuard Mastiff 8019 in backpack
    Whilst the Mastiff takes up more room than a D/U lock, I was easily able to fit it into my relatively small backpack.

    Commuters can also leave the OnGuard Mastiff locked at their destination. This way if you travel to the same location each day, you won’t have to carry the chain with you!

    Mounting System

    Unlike D/U locks, chain locks aren’t supplied with a mounting system that allows them to be attached to your bike.

    If you don’t want to carry the Mastiff in your backpack or over your shoulder, there are a few smart mounting devices that you can use to transport this chain whilst you ride.

    How to carry the OnGuard Mastiff 8019
    The OnGuard Mastiff can be carried over the shoulder, however It'd be a better long term solution to use one of the mounts suggested below

    I’m yet to test any of these out, but I’ve heard good things about the Kryptonite Transit Tube-R [Amazon link].

    This bag clips to the underside of your bike’s top tube and is held in place by two heavy-duty Velcro straps.

    Otherwise, ABUS’ Holder ST 2012 Chain Bag [Amazon Link] may be a good option.

    Quality & Maintenance

    Even with some of the best cheap bike locks, manufactures cut cost by sourcing cheaper materials which are often lower quality.

    However, since getting hands-on experience with the OnGuard Mastiff 8019, I’ve been impressed with how robust it feels.

    The 10mm chain links are covered by a durable nylon sheath. This prevents the chain from scratching your bike and keeps the chain free from dirt and grime.

    OnGuard Mastiff 8019 anti scratch nylon sheath
    The nylon sheath supplied with the Mastiff is removable and can be washed easily if it becomes dirty.

    The Boxer 8084 D/U Lock also has a soft anti-scratch coating which will keep the paintwork of your bike in pristine condition.

    The Boxer does have a plastic outer shell, which I’m not a massive fan of as plastic can easily be damaged.

    Yet, just like the OnGuard Brute and Pitbull, the Boxer uses metal end caps, which protect the outer plastic shell from drops and knocks.

    Onguard boxer anti scratch outer coating

    I’ve heard from a few sources that if the Mastiff isn’t maintained correctly, it can stiffen up and sometimes rust will begin to show.

    By regularly lubricating moving parts, you’ll be able to get the most life out of this chain lock.

    I’ve put together an extensive guide that will teach you the essentials of bike lock maintenance, have a read.

    Locking Mechanism & Operation

    The X4P locking mechanism is operated by the five keys sidewinder keys supplied with the Mastiff, one of which has an integrated LED that is helpful when using this chain lock in the dark.

    I found when reviewing the OnGuard Brute that its shackle would sometimes need a bit of encouragement to be able to lock it.

    Once or twice when I was securing my bike with the Mastiff 8019, I had to push the Boxer’s shackle into position before being able to lock the chain in place.

    OnGuard Mastiff X4P quad locking mechanism
    Here you can see the X4P locking bolts that secure the Boxer's shackle in two points on either side.

    Most of the time, with new budget bike locks, stiffness and usability issues are caused by rough edges catching on each other.

    Don’t worry, after a short period of use, any uneven edges will smoothen and the lock will be easier to operate.

    The entrance to locking mechanism of the Boxer is guarded by an automatic keyhole cover that keeps dirt and debris from getting inside.

    This is a feature which is usually only found on more premium bike locks and will increase the usable life of the Mastiff chain lock.

    How Much Does the OnGuard Mastiff 8019 Cost?

    How much does a good bike lock costThe majority of OnGuard’s high-security locks are sold at a budget-friendly price.

    The Mastiff 8019 follows this trend. Chain locks tend to be slightly more expensive than D/U locks, this is because more metal is required to produce them.

    When compared to chain locks of similar quality, the OnGuard Mastiff is reasonably priced.

    It’s not the cheapest, but many of the more inexpensive chain locks lack the extra features the Mastiff utilises, that add to its overall security and usability.

    The most up to date and competitive price I’ve found for the Mastiff 8019 can be found here [Amazon].

    OnGuard Warranty

    The Mastiff comes with a lifetime warranty which covers you from manufacturing & workmanship defects.

    Following my lock maintenance guide, and regularly lubricating the Mastiff will generally be all that’s needed to keep it working smoothly though.

    It’s nice to have the lifetime warranty for added peace of mind though!

    OnGuard Anti-Theft Protection Plan

    OnGuard’s Anti-Theft Program covers you with an extra level of security. If your bike is stolen whilst secured with the Mastiff and you’ve followed the T&Cs, you’ll be able to claim compensation.

    With the OnGuard Mastiff 8019, you’ll be covered for up to $1001 for power sport and $3001 for bicycles.

    For any claim to be successful, however, you’ll need to make sure you follow OnGuard’s long list of requirements. They’re straightforward, but it’s a long list.

    You can read more about OnGuard’s ATPO here

    How to Use the OnGuard Mastiff 8019

    Most Secure Locking Method

    As always, you should aim to secure the most expensive parts of your bike. By removing your front wheel, you can quickly secure both wheels and the frame of your bike at the same time.

    If you wanted to secure your front wheel without removing it, consider using a cable extension.

    Whilst cable extensions don’t provide a tremendous amount of security, they’ll stop chancers from pinching your quick-release wheels.

    As I’ve covered for a more in-depth security guide, read this article.

    How to use the OnGuard Mastiff 8019
    It's good practice to keep your lock off the ground, this way thieves can use tools such as sledge hammers to break them open.

    Locking Two Bikes

    I was comfortably able to secure the frame and rear wheel of two bikes using the OnGuard Mastiff.

    Great for those who cycle together!

    As stated above, using a cable extension alongside the Mastiff chain is a straightforward way to secure your front wheel. 

    (Click to enlarge)

    Included with the Mastiff 8019

    • OnGuard Mastiff Chain
    • OnGuard Boxer D/U lock
    • 5 Sidewinder keys (including 1 LED key)
    • Instructions
    • Key Code Card
    OnGuard Mastiff 8019 Sold Secure Gold

    How Does the OnGuard Mastiff 8019 Compare to Other Bike Locks?

    Kryptonite 1275 New York Noose – An Upgrade from the OnGuard Mastiff

    Kryptonite are well known for producing some of the highest quality bike locks on the market. The Max Performance steel New York Noose 1275 is slightly shorter than the OnGuard Mastiff measuring 29.5″ (75cm).

    This chain received the same Sold Secure Gold rating as the OnGuard Mastiff. However, the Noose 1275 uses higher quality materials and thicker, more secure 12mm chain links .

    Thanks to its widened end link the 1275 Noose can lasso around your bike before being threaded back through itself and locked to an immovable object.

    This essentially makes the usable length of this chain longer than that of the Mastiff 8019.

    OnGuard used to sell a version of the Mastiff chain lock with a noose end link, but they’re hard to come across now.

    If you have the budget to cover the slight increase in price, the New York Noose 1275 [Amazon link] is a worthy upgrade.

    Yale YCL3/110 – More Affordably Priced & Similar Features

    I haven’t yet had hands-on experience with the Yale YCL3, but from what I’ve heard, this chain lock is almost identical to the OnGuard Mastiff 8019.

    Yale’s YCL3 chain and lock use a quad-locking mechanism. This chain comes with a similar LED key, its chain uses the same 10mm titanium hardened links, and it offers the same Sold Secure Gold rating.

    If you liked the sound of the OnGuard Mastiff it’s worth checking out the Yale YCL3, its price [Amazon Link] changes from time to time, but it’s just as affordable as the Mastiff.

    Oxford Heavy Duty Chain and Padlock - Budget Option

    The Oxford Heavy Duty Chain and Padlock is another super budget Sold Secure Gold rated bike chain lock.

    Just like the Mastiff 8019, the Oxford heavy duty chain and padlock is resistant to all forms of attack including drilling, sawing, hammering and cropping.

    It’s impressive that a lock sold at such a budget friendly price [Amazon link] boasts the Sold Secure Gold rating.

    Usually, budget chain locks are made from substandard materials. Yet this impressive chain lock has been tried and tested & received great reviews online.

    Definitely worth a look.

    Summary - OnGuard Mastiff 8019 Review

    OnGuard have done it again with the Mastiff 8019, a maximum security, Sold Secure Gold bicycle chain sold at a budget price.

    Whilst the locks from OnGuard’s range aren’t as high quality as locks produced by Kryptonite or ABUS, they’re usually available at a more competitive price. Fortunately, the Mastiff 8019 comes with a lifetime warranty that will keep it free from manufacturing defects.

    (Click to enlarge)

    I was impressed by the Mastiff 8019, its 42″ (106cm) chain is suitable for a wide variety of locking scenarios and is capable of effectively securing multiple bikes at once.

    It’s worth remembering that the Mastiff isn’t bolt cutter proof. If you’re looking for the most secure chain possible, I’d recommend the Pragmasis Protector chains.

    Squire SS50CS Padlock Pragmasis
    If security is what you're looking for, the beefy Pragmasis Protector range is worth a look!

    The Protector chains are 16mm thick and not portable like the Mastiff, but worth a look if security is your number one priority.

    Otherwise, if you’re after a chain that offers excellent all-round usability and security, the Mastiff 8019 is the one for you. 

    If you’d like to read about some other top-rated bike locks, read about the best bike locks on the market, or the best budget bike locks

    Remember, lock it, or lose it!

    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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