Foldylock Forever Review: The Strongest Folding Lock?

Foldylock Forever Review: The Strongest Folding Lock?

Last Updated on November 24, 2023 0 Comments

There was a time when, if you wanted a high security folding bike lock, you were limited to two choices: the Abus Bordo 6500 and the Trelock FS 500. But while you’re still not inundated with options, those times have changed.

Nowadays, we can add the Kryptonite Evolution 790 and the Foldylock Forever to that short list.

It’s hardly surprising that Foldylock (AKA Seatylock) have added a high security folder to their catalog. They already have a whole series of mid-security folders, so creating something with an extra level of protection is a logical next step.

But how well did they do this? It’s not easy to make a high security folding lock for a reasonable price.

As ever, in this review we’ll look at how secure the Foldylock Forever [Amazon] is, whether it’s easy to carry around and use on a daily basis, whether it’s good value for money and, if it’s not the right lock for you, I’ll suggest some alternatives.

Let’s get into it…

Probably the most secure folding lock currently available, the Foldylock Forever is also easy to carry and a pleasure to use!


Foldylock Forever

Foldylock Forever

My score:

Rating: 4 stars

Check price:

Plate thickness:

6.5 mm


3.88 lb (1.76 kg)


35.4" (90 cm)

Foldylock rating:


Security Ratings:

Sold Secure Gold

Foldylock Forever Pros

  • It’s very secure (Sold Secure Gold)
  • Great frame mount makes transport easy
  • Smooth operation
  • Lots of locking options

Foldylock Forever Cons

  • It’s expensive
  • It’s heavy
  • Plastic key hole cover

How secure is the Foldylock Forever?

By their very nature, folding locks tend to be less secure than u-locks. The plates are thinner than a u-lock shackle, and the nuts that hold the plates together are a weak point that are vulnerable to attack.

This is probably why (along with higher production costs), there are so few high security folding locks.

However, it is possible, and the Foldylock Forever shows us how!

The plates on the Foldylock Forever are 6.5 mm thick, which is 1 mm more than all the other high security folders (Abus Bordo 6500, Trelock FS 500, and Kryptonite Evolution 790).

And 1.5 mm more than medium security folders like the Foldylock Compact and ETOOK ET510L.

Foldylock Forever plate thickness

Foldylock Forever 6.5 mm plate thickness

I’m not able to cut the 5.5 mm thick, Abus Bordo 6500 plates with even the biggest 42” bolt cutters. And I’ve never heard of anyone else having any success either. So I’d say there’s no chance of anyone cutting the Foldylock Forever plates with manual bolt cutters.

However, while the extra 1 mm will also provide extra resistance against hacksaws and other manual cutting tools, it won’t make any difference against an angle grinder.

An angle grinder will cut through all bike locks (except a very select few), in a matter of seconds. But folding locks are particularly vulnerable because:

  1. The plates are thinner than most u-lock shackles
  2. It's much easier to hold a folding lock still with one hand than a chain
  3. Folding locks only need to be cut once to open them up

Having said that, the difference in the time it takes to cut an 18 mm Kryptonite Fahgettaboudit shackle twice and the Foldylock Forever once, is not going to make much difference to a thief with an angle grinder.

He will happily (and easily) take on either, so relatively small differences between non-angle grinder resistant locks don’t make much practical difference in the street.

Here's a video of a folding lock being cut with an angle grinder (I don't know if it's the Foldylock Forever, but it doesn't matter, because they would all fare the same):

However, I still wouldn’t recommend a folding lock if your circumstances put you at risk of an angle grinder attack. If you do need a bike lock with angle grinder resistance, check these out.

As well as upping the plate thickness, Foldylock has also taken steps to address the other weakness in folding locks: the nuts that hold the plates together. On cheaper, lower security folding locks, it’s possible to work bolt cutter jaws between the plates and to cut through the bolts.

And while that trick won’t work on the high security folding locks, the Lock Picking Lawyer showed that even the Abus Bordo 6500 is vulnerable to a targeted nut splitter attack in this area!

However, it’s really important to note that thieves are not using nut splitters in the street (they only work on folding locks, which make up a tiny proportion of bike locks, and they’re difficult to use if the lock isn’t held in a vice).

So thieves are not carrying them and they are largely irrelevant!

Foldylock Forever nut protection

Foldylock Forever nut protection

However, reinforcement in this area of weakness is definitely welcome, and the Foldylock Forever has added a layer of protection around the nuts to thwart any such attacks. They can still be defeated here, but it’s much more difficult.

The extra steps that Foldylock have taken with the Forever, are reflected in its independent security testing results, as it has been awarded a Sold Secure Bicycle Gold rating. And this makes it a high security lock for high risk circumstances.

The only other folding locks with a Sold Secure Bicycle Gold rating are the Abus Bordo 6500, Trelock FS 500 and Kryptonite Evolution 790, so it’s in rarefied company.

In general, high security u-locks will be more secure than high security folding locks. But folding locks, like the Foldylock Forever, have several big advantages over any u-lock…

Is the Foldylock Forever easy to carry?

The biggest advantage that folding locks have over u-locks or chains, is probably how easy they are to carry around on your bike. And despite being very heavy (for a folding lock), the Foldylock Forever is no exception!

Weighing the Foldylock Forever

Weighing the Foldylock Forever

The Foldylock Forever weighs 3.88 lb (1.76 kg), which is around the same weight as 4.5 cans of Coke. This makes it the heaviest of the high security folding locks (x% heavier than the Abus, 11% heavier than the Trelock and 18% heavier than the Kryptonite).

This is partly due to the thicker plates and partly due to the longer length (which we will come to later). But the important point is that it’s quite heavy (it’s certainly not a lightweight lock), so you need to think about how you will carry it.

Luckily, it folds down into a nice, compact package that will easily slide in and out of the supplied frame mount.

Foldylock Forever fame mount

Foldylock Forever fame mount

The frame mount is a simple plastic cradle which you can either screw into the holes in your frame that are designed for a water bottle cradle (the screws and hex key are included), or fasten anywhere on your frame using plastic ties (also included).

I always much prefer the first option (screw it into the frame), as it’s really quick and easy to install, it provides a very stable connection and there are no annoying and untidy trailing plastic ties or Velcro.

Not everyone will have that option though (either they won't have the necessary holes in their frame or there will be something else already in the way, e.g. the water cradle). So it’s nice to have the plastic ties as well.

Here's a nice video on how to install the mount both ways:

I tried both, and both worked well. You do get the slightly annoying bits of trailing plastic if you go with the second option, but you could always trim them off with a pair of scissors if you're really fussy like me.

The cradle itself is made from very smooth, heavy-duty plastic. Unusually, there is no strap to hold the lock in place while it’s inside the frame mount (as there is with the Abus and Trelock mounts). Instead, the system relies on the tight fit of the cradle around the lock to keep everything in place.

Foldylock Forever vs Abus Bordo 6500 cases

Foldylock Forever case (no strap) vs Abus Bordo 6500 case (with strap)

So when you push the Foldylock Forever into the cradle, there’s a small lip that flexes out slightly to allow the lock entry. Once the lock is properly seated at the bottom of the cradle, the lip flexes back across the top of the lock to keep it in place.

Pulling at the top of the lock is enough to make the lip flex out again, so that the lock slides out easily.

The advantage of this system is that it makes getting the lock in and out of the mount quicker and easier, as you avoid the extra step of fastening and unfastening a restraining strap over the top.

Foldylock Forever in frame mount

Foldylock Forever in frame mount

I have read some reviews that suggest the fit is too tight and that makes it difficult to get the lock out of the holster. Foldylock use the same system on all their folding lock frame mounts, so I have tested them a lot, and I never found this to be an issue.

It’s tight for sure, but a good tug is all that’s needed.

Another nice feature of the mount is that it’s entirely rattle free. The tight fit means a silent ride, which I know is very important for many!

If, for whatever reason, you can’t use the frame mount, then the compact folded up package means it can be slipped into a bag very easily. Just bear in mind that it’s heavy for a folding lock. It might be small, but it's the same weight as 4.5 cans of Coke, remember.

Foldylock Forever with Coke

Foldylock Forever: small and compact

All in all, the Foldylock Forever is very easy to carry around. In fact, it’s one of the most portable high security lock I’ve tested (the others being the wearable Liteloks and Hiploks).

Is the Foldylock Forever easy to use?

I found using the Foldylock Forever a breeze. A lot of thought has gone into this from Foldylock, and I think they have got it just right.

From being able to slide it out of the case without having to unstrap it first, to the ease with which it unfolds, everything runs very smoothly for such a heavy-duty lock. The plates move much more smoothly and quietly than those of the Abus Bordo 6500 for example.

Foldylock Forever unfolded

The Foldylock Forever moves very smoothly

The Abus Bordo is also covered in a slightly sticky rubber, which isn’t as tactile as the harder plastic that covers the Forever. It might be that the soft rubber of the Abus is less likely to scratch your paintwork, but I certainly haven’t noticed the Foldylock causing any problems on my bike!

As for locking your bike with the Foldylock Forever, it has the same advantages and disadvantages of any other folding lock.

In a quiet bike rack, it’s probably a bit quicker and easier to use a u-lock, as you can just line everything up and shove the shackle through to meet the crossbar on the other side. While with a folding lock, you always have to thread one end around and back to join the body. It’s a bit more fiddly.

Foldylock Forever around front wheel

Foldylock Forever around front wheel

Whereas in a busy bike rack, getting everything lined up for a u-lock can be more challenging, and you start to really appreciate the flexibility of a folding lock, and it’s ability to create irregular locking shapes!

Likewise, if you don’t always use a bike rack and sometimes have to use other street furniture, the flexibility of a folding lock is really useful. Lampposts, park benches, railings, street signs etc. are all much easier with a folding lock.

Foldylock Forever around back wheel

Foldylock Forever around back wheel

The Foldylock Forever is only available in one size and that’s with a 35.4” (90 cm) circumference. The Abus Bordo in contrast, comes in two sizes 33.5" (85 cm) and 43.3" (110 cm).

Foldylock Forever vs U-lock

Foldylock Forever: more locking space than a standard size u-lock

I much prefer the Foldylock Forever length, which gives you slightly more internal locking space than a standard size u-lock. In contrast, the shorter Abus gives you slightly less space and the longer Abus starts to get really heavy.

Keyhole Cover

To protect the locking mechanism from water and grime, the Foldylock Forever features an indented keyhole cover that splits in two when the key is pushed into the lock and automatically closes when the key is removed.

Foldylock Forever key hole cover

Foldylock Forever: plastic key hole cover

I like the fact that I don’t need to remember to close a cover manually. And these type of covers seem to reduce disc misalignment when the key is exiting, which is something that can be really annoying.

However, I do worry about the key pushing any dirt that has accumulated on the outside of the cover inside the mechanism. I would also prefer to see this cover made of metal (as it is in Abus, OnGuard and Zefal locks), rather than plastic, since this part of the lock is subjected to a lot of wear and metal would last much longer.

Keys and Warranty

You get 3 laser cut (or “sidewinder”) keys with the Foldylock Forever. You also get a key code card which enables you to order more, should you need them,

Foldylock Forever keys

Three keys and a key code card

Plus a standard three-year warranty when you register your lock through their website.

Conclusion: Is the Foldylock Forever worth it?

Folding locks are always more expensive than u-locks that provide similar levels of security. And high security folding locks are particularly expensive. For instance, all the folding locks I mention in this article tend to cost over $100 or £100.

So if you choose the Foldylock Forever (or any other folding lock), it’s because of their superior portability and/or practicality, rather than any amazing security to price ratio.

Foldylock Forever around lamppost

Foldylock Forever around lamppost (lots of locking options)

But with the Foldylock Forever, you are getting a very high level of security (it’s probably the most secure folding lock currently available), plus an easy-to-use frame mount that gives you great portability and a 5.4” (90 cm) circumference that will give you lots of locking options.

For me, it’s more secure, a bit easier to carry and much easier to use than the Abus Bordo 6500, so I’ve given it the “best high security folding lock” award in my best bike lock round up of 2023!

Yes, it’s a little bit more pricey (check the price at Amazon), than most high security u-locks, but you are paying for that extra level of practicality.

Of course, if you decide it’s not for you then there are alternatives…

Alternatives to the Foldylock Forever

Looking for something cheaper?

OnGuard Pitbull Standard

If the Foldylock Forever is just a bit too expensive, then I don’t recommend that you look at a cheaper folding lock.

It will inevitably be less secure. And you should never make compromises in security!

Instead, I’d recommend a u-lock. OnGuard make some really good value, high security bike locks.

The Pitbull range [Amazon] all provide Sold Secure Diamond levels of security (although not all of them are officially rated). So they’re all actually more secure than the Foldylock Forever!

They come in a range of sizes (including a particularly long model). And they are wider than most other u-locks. So for a u-lock, you’ll get more locking options than with many other brands.

They also come with a decent frame mount. However, as with all u-locks, the portability won’t be as slick as you’ll get with the Foldylock Forever.

But you can usually get an OnGuard Pitbull for much less than half the price of the Foldylock Forever. So if price is a priority, and you’re prepared to make a compromise in terms of usability, they are a great choice!

Looking for something lighter?

Seatylock Mason 140

The Foldylock is a pretty heavy lock. If you’re looking for something lighter, then the Kryptonite Evolution 790 folding lock weighs slightly less (0.6 lb or 260 g, which is less than a can of Coke).

So not much lighter. And it’s less secure and around the same price, so the small weight saving is probably not worth it!

Instead, you could go for another u-lock.

The Seatylock Mason 140 [Amazon] is made by the same company that makes the Foldylock Forever and is one of the lightest Sold Secure Diamond rated bike locks available.

Weighing 2.13 lb (0.97 kg), it’s nearly half the weight of the Foldylock Forever, plus it’s more secure, and cheaper.

However, it’s a mini u-lock, so you’re pretty much restricted to bike racks, and even then you might struggle in some situations and with some bikes. But if weight is a priority, it’s a great high security, lightweight choice! 

Foldylock Forever Specs

Foldylock Forever

Foldylock Forever

My score:

Rating: 4 stars

Check price:

Plate thickness:

6.5 mm


3.88 lb (1.76 kg)


35.4" (90 cm)

Foldylock rating:


Security Ratings:

Sold Secure Gold

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About the author 

Carl Ellis

I've had bikes stolen in London, New York and Barcelona. Yep, I was a serial, international, bike theft victim. In 2015 I decided to stop the rot. And not a single bike's been stolen since! Brakes, yes. Bells, yes. But they're another story. Everything I learn, I document on this website. More about my story. Contact me. LinkedIn.

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