The latest addition to the rapidly expanding variety of angle grinder resistant bike locks is the Squire Stronghold D16 MAX.
The Squire Stronghold D16 MAX is one of the biggest of these locks, putting it in direct competition with other behemoths like the Hiplok DX1000 and the Abus Super Extreme 25000, and probably making it most suited to ebikes and motorbikes.
But how does it compare to these other locks, and is it good value? I’ve been testing the Squire Stronghold D16 MAX for a couple of months to find out.
First, I look at how secure it is by attacking it with an angle grinder. Then I evaluate how easy it is to carry around and use on a daily basis. And finally, I suggest some alternatives if it’s not the right choice for you!
Very expensive considering it's average performance compared to other angle grinder proof locks.
Summary
Squire Stronghold D16 MAX Pros
Squire Stronghold D16 MAX Cons
How secure is the Squire Stronghold D16 MAX?
The Squire Stronghold D16 MAX is just like any other, high security steel u-lock. Except, that is, for the layer of “tungsten carbide” fused to the outside, to protect it from angle grinders. Which is a similar technique employed by many of the other angle grinder resistant bike locks.

Squire Stronghold D16 MAX: looks like a regular u-lock
And like every other angle grinder resistant bike lock (except for the OnGuard RockSolid), the Squire Stronghold D16 MAX has received the highest possible, Powered Cycle Diamond rating from Sold Secure.
Which means it’s a very secure bike lock indeed!
But how well does it compare to the other locks in this category? I tested it against both regular and diamond angle grinder discs to find out.
Against Regular Discs
Using regular angle grinder discs, I was able to cut one side in 1:22 min using 3 discs. And while I didn’t cut the other side, if we extrapolate the numbers, it seems like it would require 5 or more discs and over 2:44 min to cut both sides.
Which is good but not spectacular compared to the other angle grinder resistant bike locks.
What is more concerning, is that after one cut, I was able to twist the shackle to create quite a big gap. Whether this was big enough to work the lock off a bike (without cutting the other side), I’m not sure.

There was quite a big gap after 1 cut
And it’s true, a good locking technique, which fills the inside of the shackle, should mitigate any risk here significantly.
But the gap was certainly larger than with any of the other angle grinder resistant locks I’ve tested, so that’s not great!
Against Diamond Discs
I also tested the Squire Stronghold D16 MAX against a diamond angle grinder disc. I was able to cut one side in 1:46 min, which is the second-fastest time, after the SkunkLock Carbon. So again, not a great result.

Squire Stronghold D16 MAX vs diamond disc
Attack at Base of Shackle
A lot of the angle grinder resistant bike locks seem to have a weakness at the base of the shackle, where it meets the crossbar (the Abus Super Extreme 2500, for example, is particularly weak here).
So as part of my tests, I have started using regular discs to attack all the locks at this point, to see how they stand up.

Squire Stronghold D16 MAX cut at base
I was able to cut the Squire Stronghold D16 MAX in 55 seconds, but I needed 2 discs to get through it, which is a pretty good performance.
What about its performance against other types of attack?
Other Types of Attack
The 16 mm thick shackle cannot be cropped by even the biggest 42” manual bolt cutters. The 6 pin cylinder is highly pick resistant (not that bike thieves actually pick locks). And the mechanism is also well protected from drill attacks.

Squire Stronghold D16 MAX shackle diameter
So have no doubt: this is a very secure bike lock, which is going to be very difficult for a thief to defeat.
But there are plenty of other locks that are more secure, and as we’ll see, I’m not sure the Squire Stronghold D16 MAX offers too much else to balance that out…
Is the Squire Stronghold D16 MAX easy to carry?
Weighing a hefty 2.84 kg (6.26 lb), the Squire Stronghold D16 MAX is the heaviest angle grinder resistant bike lock on the market at the moment.

Squire Stronghold D16 MAX weight
And that weight is equivalent to 7.5 cans of Coke, which is a lot to be carrying around on a bicycle every day!

It weighs the same as 7.5 cans of Coke
It’s also pretty bulky. Exterior measurements of 6.3" x 12" (16 x 30.5 cm) make it one of the biggest angle grinder resistant bike locks, as well. Only the Hiplok DX1000 and Abus Super Extreme 2500 rival it for size.
While the Squire Stronghold D16 MAX doesn’t come with a frame mount, you can buy one separately. It’s called the Transporta and is a neoprene pouch that is designed to strap to your frame in various places.

Squire Transporta frame mount
It’s a very tight fit on the Squire Stronghold D16 MAX, but the lock does go in easily, and the tight fit means that the lock doesn’t move about while in there, which is good. Once zipped up, you can then strap it to your frame using the 4 Velcro straps provided.

It's a tight fit!
On the back of the pouch are a series of loops, and you just push the straps through these and then tighten them around your frame.
Easy enough. Except for finding somewhere on your frame that can accommodate such a big lock!
Let’s be honest: the Squire Stronghold D16 MAX isn’t really intended for my skinny city bike. It’s unnecessarily big. It’s really designed for chunky ebikes and motorbikes. And Squire’s instruction video for the Transporta reinforces that, by using an ebike…

My bike's long handlebar stem
My bike does have a really long handlebar stem though, so there was actually enough space to strap it to the handlebars, without it interfering with the front wheel. And it didn’t interfere with the steering as I was riding about either.

The unusually long handlebar stem means there's just enough room!
In this way, it worked really well.
But the lock is so long, that this won’t be the case for most bikes. On most bikes, there simply won’t be enough room to dangle a 12” (30.5 cm) lock off the handlebars, without touching the front wheel.

It straps to the frame relatively easily
I also tried to strap the Transporta to my frame, much like you can with the Hiplok D1000 frame pouch. But while I could attach it well enough, it got in the way when I was riding. Either brushing my knee or my thigh, depending on where on the top tube I put it.
If you have a chunky ebike then you might have more luck. Attaching it to a luggage rack (as in the video) looks like it would work really well.

But it's too long for the frame here. It gets in the way when riding
But the one thing I don’t like about all these Velcro strapped pouches, is what to do with them when you’ve locked your bike up. Getting them on and off the bike is far too fiddly to be doing it every time you lock up. But if you leave them on an unattended bike for any length of time, I can imagine they would be stolen pretty quickly.

The Velcro straps make it easy to steal if you leave it on the bike.
So what do you do?
As an alternative, you could try one of the third party, universal mounts like the Huldit or the Kryptonite Transit H Bar [Amazon], but make sure the Squire Stronghold D16 MAX will fit these mounts, before you commit to buying one.
And these all use Velcro straps too!
Personally, I’d rather just throw the lock in a bag. It went in my saddlebag easily enough. There just wasn’t a lot of room for anything else, with it in there!

Squire Stronghold D16 MAX in my saddlebag
But it’s important to think about how you'll carry the Squire Stronghold D16 MAX around before you buy it. Because if you can’t come up with a practical method, you will stop using it, and that of course is when your bike gets stolen!
Is the Squire Stronghold D16 MAX easy to use?
The internal measurements of the Squire Stronghold D16 MAX are a very generous 3.70" x 8.58" (9.4 x 21.8 cm) so you shouldn’t be short of options when you’re trying to find somewhere to secure your bike.

Squire Stronghold D16 MAX internal dimensions (narrow and long)
And once you find somewhere, the considerable internal shackle space means it should be a pretty easy to fit the lock around your bike.

Squire Stronghold D16 MAX around back wheel
On my skinny city bike, it’s overkill, to be honest; I just don’t need such a big lock. So the Squire Stronghold D16 MAX is likely to work better with bigger ebikes, chunkier town bikes, and motorbikes.

Squire Stronghold D16 MAX around seat stays
But whereas it is very long (only the Abus Super Extreme 2500 and the SkunkLock have more internal length), it’s actually very narrow. Narrower than all the other angle grinder resistant bike locks except the mini u-locks, the Hiplok D1000 and OnGuard RockSolid.

It's too narrow to fit around a traffic light
And this means while I was able to fit locks like the Hiplok DX1000 around fatter street furniture like traffic lights, I wasn’t able to get the Squire Stronghold D16 MAX round such objects, which reduced my options somewhat.
Keys and Mechanism
You get 2 keys and a card with a code for ordering more (should you need them), with the Squire Stronghold D16 MAX. In my experience, the keys worked smoothly, and I had no problems locking and unlocking.

You get two keys and a key code card
There is a slightly frail and loose feeling plastic slider to protect the mechanism from water and street grime.

Squire Stronghold D16 MAX key hole cover
And I should just add that the plastic that covers the crossbar also feels a little thin and brittle. I’d imagine a couple of accidental drops onto the street and this cover would crack and come away from the crossbar.
Conclusion: Is the Squire Stronghold D16 MAX worth it?
Have no doubt: the Squire Stronghold D16 MAX is a very secure bike lock. It has the highest possible rating from Sold Secure. And in my tests, it required several angle grinder discs and a number of minutes to defeat it.
So it’s very unlikely that any thief is going to defeat this lock in the street.
But the thing is: its performance was quite average compared to the other angle grinder resistant bike locks I’ve tested, while the price you’ll pay for this lock is usually at the very top end.

Squire Stronghold D16 MAX unboxed
In fact, the last time I checked, the Squire Stronghold D16 MAX is the most expensive angle grinder resistant bike lock on the market (check Amazon price here)
If it was also the best performing lock, this price would be justified. But it’s not.
And the fact that there is no frame mount or other transport options available for the Squire Stronghold D16 MAX, that the plastic housing feels a little cheap and brittle, and that it’s perhaps a bit too narrow, don’t help it either.
If you’ve got a bulky ebike or motorbike that requires a big lock, and won’t struggle to carry the weight (due to being powered bikes), and you can find it for a better price, then it's definitely a good option.
Otherwise, I would look at some of the alternatives…
Alternatives to the Squire Stronghold D16 MAX
Looking for better value?
The Hiplok DX1000 is roughly the same size as the Squire Stronghold D16 MAX.
But it’s a bit wider, so it should provide more locking options.
And it’s a bit lighter, so it should be easier to carry.
And although there is no frame mount available for the Hiplok DX1000 at the moment, they are releasing the BR1000 in Spring 2025, which will make it even easier to carry!
Most importantly, it is both more secure and cheaper than the Squire Stronghold D16 MAX. So it’s a bit of a no-brainer really: the Hiplok DX1000 is a great alternative to the Squire Stronghold D16 MAX (check Amazon price here)!
Looking for something smaller & lighter?
The Squire Stronghold D16 MAX is very big and very heavy. And the truth is, most cyclists probably don’t need such a big bike lock.
The Litelok X3 is more of a standard size u-lock. And it’s 26% lighter at 2.09 kg (4.60 lb), which is about the same as 5.5 cans of Coke (rather than the 7 cans of Coke for the Squire Stronghold D16 MAX).
Like the Hiplok DX1000, it’s both more secure and cheaper than the Squire Stronghold D16 MAX.
Plus, it’s available with a great frame mount.
So if a more regular size bike lock is what you need, the Litelok X3 is a fantastic alternative to the Squire Stronghold D16 MAX (check price here)!
Squire Stronghold D16 MAX Specs
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