Kryptonite New York Diamond Review: From Zero to Hero?

Kryptonite took a long time to release their angle grinder resistant bike lock. In fact, they were the last of the big brands to do so.

And that should have given them enough time to get things exactly right. But unfortunately they didn’t.

I bought my Kryptonite New York Diamond from a big European website in April 2025. And in my first round of testing, it performed exceptionally well. However, when I attacked the bottom of the shackle, I was able to cut through it in just 13 seconds with 1 angle grinder disc.

This is because the anti angle grinder material didn’t extend to the bottom of the shackle.

When Kryptonite saw the video of this, they got in touch to tell me that my lock must be part of a faulty batch. And they offered to send me a new lock for re-testing.

Read on to find out how the new lock performed…

How secure is the Kryptonite New York Diamond?

The New York Diamond certainly looks like a serious prospect. It’s essentially a slightly more compact version of the long-established (and very secure) New York Standard, with a new “diamond” coating around the shackle and crossbar.

This coating is specifically designed to destroy angle grinder discs during an attack, just like the coating on the other angle grinder resistant bike locks.

However, each brand implements the coating in a slightly different way. In Kryptonite’s case, there is a standard 16 mm hardened steel shackle, encased in a 1 mm thick sleeve made from this “diamond” material (which is presumably some kind of carbon).

Unlike other brands (like Litelok and OnGuard), the anti angle grinder material isn’t fused to the surface of the shackle, Instead it is more like a tube that surrounds (and protects) the steel shackle inside.

By the way: Kryptonite advertise the shackle as being 26 mm thick. But that’s only if you include the thick vinyl coating. The actual hardened steel part is 16 mm. The carbon sleeve is 1 mm thick.

When you include the small space between the sleeve and the shackle, it all comes to about 22 mm of protective material.

That’s still more than enough to stop manual bolt cutters (of every size), and makes for a very solid lock, but the misleading 26 mm measurement is quite annoying.

My initial tests on the first lock were really encouraging. It took me 13 discs and 3 minutes 11 seconds of cutting to break through the top of the shackle.

That’s a genuinely impressive result. In fact, only the SkunkLock Carbon has done better in my tests (14 discs). Even a diamond disc barely made a scratch in 2 minutes of screachingly loud cutting.

However, when I attacked the area where the shackle meets the crossbar with a regular disc, I got through it in just 13 seconds with 1 disc (which was completely undamaged when I finished).

As mentioned in the introduction, this was because the diamond coating didn’t extend all the way to the base of the shackle, which is the exact same flaw that plagued the Abus Super Extreme 2500.

However, things were very different when I tested the new lock that Kryptonite sent me…

This time it took me 25 discs and over 6 minutes of active cutting to break through the base of the shackle.

You can see both tests in the video below:

Obviously, this time, the anti angle grinder material did extend the full length of the shackle. And now we have a very impressive result at the base of the shackle too. In fact, no other lock I have tested has performed as well at the base of the shackle.

It’s also important to note that there was very little movement in the shackle when it has been cut once. Which means that a thief would definitely have to cut the shackle twice to steal your bike.

I also had a go at the crossbar, and found that was protected by the anti angle grinder material too.

So how secure is the Kryptonite New York Diamond, really?

Well, the second lock is probably the most angle grinder resistant lock I have tested to date.

Only the Litelok X3 took (just slightly) longer to cut at the top of the shackle, but I needed far more discs to get through the Kryptonite. And at the base of the shackle, it outperformed the other locks by miles.

But of course the first lock was the poorest angle grinder resistant lock I have tested to date.

So it depends on which one you get!

Hopefully, Kryptonite have sorted out their manufacturing issues and there are no duds in circulation now.

Is the Kryptonite New York Diamond easy to carry?

At 2.2 kg (4.92 lb), this is not a light lock. And with internal dimensions of 8” x 3.75” (20.4 cm x 9.5 cm), it’s not small either.

It’s around the same size as the Litelok X3 and just a little bit heavier, weighing about the same as 6 cans of Coke.

So carrying it around could be a bit of a chore.

Thankfully, Kryptonite include their Flexframe-U Bracket when you buy the lock. This frame mount is the same one as you get with all Kryptonite bike locks, and it has a pretty bad reputation.

But I actually quite like it…

It’s easy to install, and as long as I tighten it enough, it always remains stable for me. I do find it works better on the seat tube than the down tube. But while I was riding around, the New York Diamond barely moved in the mount at all.

Clipping the lock in and out of the bracket is really straightforward. Much quicker and easier than with the frame mounts from other brands, which are more fiddly to use. And more fiddly to install too, by the way.

To be honest, I was really surprised at how well the Flexframe-U Bracket worked. I’d always presumed that the heavier Kryptonite bike locks (like the Fahgettaboudit) didn’t come with a frame mount because the locks were just too heavy to properly support.

But the Flexframe-U Bracket copes really well with the New York Diamond Standard.

And apart from being easier to install and use than the frame mounts from other bike locks, unlike most of them it’s included when you buy the lock, rather than being an add-on that costs extra.

Of course, if you don’t have space on your frame, the lock fits easily into most saddlebags or backpacks. So there are options.

Is the Kryptonite New York Diamond easy to use?

With “standard sized u-lock” internal dimensions, the New York Diamond is big enough to accommodate all kinds of locking scenarios and all types of bike, including chunky city bikes and ebikes.

I was able to lock my slim city bike in a number of different ways: through the down tube and front wheel, the seat tube and back wheel, and the seat stays and back wheel.

With bigger bikes, you may need to adjust your locking style somewhat, but you should always be able to find a way to secure it properly.

The build quality of the New York Diamond (like all the Sold Secure Gold and above Kryptonite locks) is really good. It feels like a premium product. The hard rubber shackle cover is thick and tactile. Likewise, the plastic casing that protects the crossbar feel like an integral part of the lock.

This is in contrast to locks like the SkunkLock Carbon and the Squire Stronghold D16 MAX where the plastic casing feels much cheaper and more flimsy, and likely to break and fall off if dropped.

Keys and Mechanism

Kryptonite provide three keys and a key code (in case you want to order extras) with the New York Diamond.

Personally, I prefer the slider keys used by brands like OnGuard. Kryptonite use a disc detainer mechanism, which is theoretically more secure, but given that bike thieves don’t bother picking locks, that’s kind of irrelevant.

The real issue is that if you insert the key only halfway and try to turn it, you can misalign the discs inside the lock. And that can be a pain to fix.

The keyhole has a sliding cover to protect it from water and dirt, which is great. But it does mean an extra step every time you lock or unlock your bike.

Conclusion: Is the Kryptonite New York Diamond worth it?

If you get one of the good ones, then yes, absolutely!

It is probably the most angle grinder resistant bike lock I’ve tested so far. The build quality is top-notch. It comes with a useable frame mount. And the price is very competitive (check Amazon price).

If I’d tested the second lock first, then I would be recommending the Kryptonite New York Diamond as a great alternative to the Litelok X3 and Hiplok D1000 and DX1000. For many cyclists, it will be the better choice.

However, the faulty first lock makes me hesitate slightly.

I’m sure Kryptonite will fix their manufacturing issues. And that the faulty locks will drop out of the supply chain.

But it’s impossible to know if you’ve got a faulty one or not. So I still feel a bit uncomfortable recommending the Kryptonite New York Diamond without reservation at the moment.

And don't forget: not everyone needs an angle grinder resistant bike lock, check out my guide to the best bike locks to find out more!

Alternatives to the Kryptonite New York Diamond

Looking for something smaller?

You can check the price [Amazon] of the Hiplok D1000 or read my full review for more details!

Looking for the best all-round security?

You can check the price of the Litelok X3 or read my full review for more details!

Kryptonite New York Diamond Specs

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