Squire Stronghold D16 Max

The Squire Stronghold D16 Max is an absolute behemoth of a bike lock. It’s Sold Secure Powered Cycle Diamond, meaning it’s obtained the highest level of security appropriate for e-bikes and even motorbikes. It’s a tungsten carbide-reinforced addition to the small stable of angle grinder-resistant locks that are effectively bifurcating the lock market: those that can resist angle grinders, and those that angle grinders go through in a matter of seconds. The Stronghold moniker is not misused here: it offers fortress-like security – and fortress-like weight.

There are two types of people in this world, those who have lost data, and those who will lose data. This is an old saying from the early days of computing, entreating people to back up their files and documents – the moral of the story being you can’t fully understand the horror of losing your work/photos until you find them gone, and so burned will you be by this, you’ll never let it happen again.

I sort of feel like this about bike thefts now. I’ve had three bikes stolen, and two thwarted attempts. There’s still (effectively) no way to completely protect any bike, there’s only best practice, including a strong two-pronged approach: the best lock that’s possible (and practical), and the best insurance policy you can find.

My last encounter with theft was a thwarted attempt. Some idiot with an angle grinder went through my sturdy (Gold-rated) lock depressingly quickly. The theft was foiled by a member of the public challenging the would-be thief and recording him, just as he had got through the stouter of the two locks on my bike, and he ran off. Thank you, good Samaritan.

Two-pronged approach

Insurance is your last resort, when all else – ie your lock – fails. There’s a healthy amount of choice, but in an industry largely competing on price, policies have limitations and exclusions enabling them to come in at lower costs. ALWAYS read the policy, criteria and fine print and check you’re actually covered for how you’d use/store/lock your bike, and duration of coverage. Personally, I have Laka insurance (a brilliant insurance scheme), a trial of which came with my Tern, and it took care, through Fully Charged, of the minor repairs very elegantly, a result of the attempted theft.

> Bicycle insurance compare quotes and find yourself a great deal to get your bike covered

Despite having excellent insurance, when angle grinder-proof locks became a thing, I knew I had to get one.

There’s a variety of different ‘angle grinder-resistant’ – probably more accurate than ‘proof’ – locks on the market currently. And as far as I can see the British-made Squire Stronghold D16 Max is about the most sizeable.

First impressions: blimey. This thing is a substantial unit. You need to be in great condition just to lift this 2.78kg beast of a lock. Very nearly half the weight of a complete Scott Addict. The weight is absolutely a consideration for most people, and sadly there seems to be vaguely proportional relationship between weight and security. It’s not exact or without exception, but roughly ‘more steel equals safer’. I used the Squire Stronghold for my Tern e-bike, where it sits happily at the bottom of the cargo box, and of course I don’t notice the weight, but I would certainly think long and hard about carrying this on a fully pedal-powered bike.

It’s probably most at home being left at one end of a bike journey – your home or work place – secured to an immovable object. In fact, that weight is just for the lock, it doesn’t come with any form of carrying aid, which perhaps speaks volumes as to whether people are expected to travel with it, or leave it at one end of their journey.

It’s the heaviest D-lock I’ve found, and the heaviest in our recent lock tests – and by a decent margin, too. It’s 394g heavier than the Kryptonite New York, 573g heavier than the Abus Granit Super Extreme 2500 (full review to come), 597g heavier than the Litelok X3, and 755g heavier than the Hiplok D1000 Anti Angle (though this is a fair bit smaller).

So is weight good or bad? Well, it’s both. Heavy means more metal, more metal means harder to cut through. Roughly. There’s so much metal here that, like the other angle grinder-resistant locks, they’re simply too chunky to be sheared by even the largest bolt croppers. And modern alloys, compounds and other wonder materials have come to locks to resist angle grinders too. Let’s be clear, though, if you have to cut your own lock at some point for whatever reason, it can be done, it’ll just require considerably more time, cutting discs, and batteries.

On the plus side, a would-be thief might be intimidated by the sheer size of it.

To forgive the weight a little, the Stronghold is one of the longest in terms of internal shackle length. This is useful for me because my Tern e-bike, being a cargo bike, is built to take 200kg, so its tubes are pretty substantial and solid. A long (and wide) shackle is a prerequisite to fit its girthy tubes within and get round a railing/bike stand. It does mean you need to be a little choosier with your parking spot – it’ll just go round a bike stand, or purpose-made anchor, but lamp-posts are mostly impossible. (Though this is true of all D-locks.)

However, the sheer heft of the lock does mean manoeuvring it, when trying to get it around anchors and bike stands, often with an arm passed over or through the bike, rather cumbersome. It’s fine for me, but I did think that my partner would find it considerably more challenging to use, perhaps to the point she just wouldn’t.

Real-world testing

In the road.cc lock-busting test, Dodgy Dave couldn’t get the bolt-cropper jaws around the Squire’s chunky 16mm steel, encased in a thick covering of TPE (Thermoplastic Elastomer) moulding. It’s the thickest-looking shackle I’ve seen on a D-lock. When Dave deployed his battery-powered angle grinder and a fresh disc, after two minutes, although the disc had more or less survived, Dave hadn’t made much progress on the lock, stipulating that he ‘didn’t get through a lot of metal’.

The difference between this new raft of locks and even the hardiest of a couple of years ago is night and day. The Kryptonite Evolution 790 Folding Lock, for example, still very new, with its Sold Secure Gold rating, fell to the angle grinder in a meagre 23 seconds. So anything that, like the Stronghold D16 Max, looks like it’ll hold out for perhaps 10 minutes or so, will mean several discs and perhaps multiple batteries.

Plus points

The locking mechanism here feels very definitive; it’s well made and secure. The key will only come out when the lock is in the ‘locked’ position.

The thick rubber coat over the metal is great – it’s substantial and solid enough to not get scuffed or nicked (no pun intended) by normal use, and ‘gentle’ enough that I didn’t worry about my frame coming off worse in an encounter with it.

Not so plus points

The thick base bar is covered in a plastic shell, which has no impact on performance or security, but it flexes a little, and feels and sounds sort of hollow if you tap it. This is the most expensive, most substantial lock in our recent round-up, and the cheap feel of this shell was incongruous with its price.

And then there’s a sliding – again, very flimsy-feeling plastic – weather cover/guard. It does not stay closed if gravity wants to pull it open. I videoed it. Be careful which way you put the lock on, because the cover will fall open under its own weight, so for full rain protection you need to use it ‘the right way round’. Again, it feels like a small thing, but it’s slightly disappointing to see at this level and price.

Value

This lock has been pretty good for me – it does what it says on the tin. And I think it provides a daunting obstacle (I think/hope) to would-be thieves with power tools. However, there are lighter and cheaper options that can also withstand angle grinder attack.

As well as being 394g lighter, the Kryptonite New York Lock that Mat tested is £20 cheaper, and it destroyed the angle grinder disc we used, reducing it to dust and smoke in about 30 seconds.

And the OnGuard Rock Solid 8590 (full review to come) is nearly £100 less, half the weight of the Stronghold D16 Max, and, like the Kryptonite, it turns a grinder’s kinetic energy against its own disc, reducing them to dust and smoke. It’s one of only two locks in our test to score 100 overall. It’s not as ‘long’ as the Squire, though.

The Abus Granit Super Extreme seems broadly comparable on paper in terms of size and resistance, though it’s a tenner cheaper and a lot lighter.

Shout about it!

The only thing I wonder about these locks is why they don’t shout about their angle grinder resistance more prominently. The Squire is a plain black lock, which barely hints at its resistance to angle grinders. It says ‘Anti-Angle Grinder’ below the Squire logo, in a font no taller than 2mm or so, when the Squire logo is perhaps 10 times the size.

The cycling industry frequently employs bio-mimicry to copy the best ideas from nature, surely it should take a leaf out of the poisonous/venomous creatures’ handbook? They advertise their toxicity with bright warnings. Shouldn’t anti-angle grinder locks do the same? Big, bright luminous letters that warn you, you’ll ruin your disc, and you don’t have enough batteries to get through me…

Who wants their £300 lock damaged by failed attempts? We want would-be thieves not just to fail, but to not even try…

Do thieves keep up to date with new lock releases? Even if they did, differentiating this Stronghold D16 Max from the non-Max version is nearly impossible. Genuinely, answers in the comments please: why aren’t all the locks festooned in capital letters that say, ‘I’m angle grinder proof, don’t even try it’? Kryptonite uses bright colours to draw attention to its lock – see the Kryptonite yellow on a lock and just walk away…

Should you buy it?

The Stronghold D16 Max is a specialist lock. The Kryptonite and OnGuard are lighter, cheaper, and equally secure/resistant, if not even more so. So, who is this for? Well, it’s so substantial, it’s plainly for the e-bike/cargo bike and motorbike crowd who need the shackle size and length. And as the owner of a Tern, that includes me.

It’s long and intimidatingly big, so hopefully just its size scares off opportunist angle grinder-touting louts, and it’s long enough to get around your bike tubes.

The fact that it doesn’t come with any kind of frame mount or carrier (though a neoprene carrier is available) perhaps speaks to the fact that Squire doesn’t really expect people to mount this in the triangle of their bike. Maybe the size is a feature not a bug.

It’s an unusual proposition: if you need the length, it’s a toss-up between this and the Abus, both of which cover all bases. If this is a consideration, Squire is a nearly 250-year-old British company, which stands behind all its products with a 10-year guarantee – so it might come down to whether you want to buy Abus, or buy British.

I just hope Squire fixes the weather cover for the lock in the next iteration.

Verdict

Absolute anchor, in terms of security and weight – buy if you need the longest shackle and the highest tier of security

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