Kryptonite KryptoLok 685 Folding Lock review

A folding lock for moderate-to-good security, with extra reach.

Kryptonite Kryptolok 685 folding lock
(Image: © Rob Clymo)

TechRadar Verdict

The Kryptonite KryptoLok 685 Folding Lock might not appeal to everyone, as it can be a little unwieldy to fold out, lock up and subsequently pack away again. However, if you need a lock with extra reach, for bikes with big wheels or thicker tyres, this is an excellent solution. It can be extended to 85cm, which means it can stretch around a couple of bikes and secure them to a lamppost to boot. The design and construction us everything you’d expect from the Kryptonite brand and its weight is handled admirably thanks to an included plastic bracket, which lets you fix it to your bike frame.


  • +

    Rock-solid construction

  • +

    Plenty of reach

  • +

    Key Safe program


  • -

    Quirky foldable design

  • -

    Reasonably heavy

  • -

    Only 'moderate' security

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One minute review

The Kryptonite KryptoLok 685 Folding Lock is another offering from Kryptonite, a respected cycle accessory brand and maker of some of the best bike locks around. The main bonus with the 685 is the foldout design, which collapses into a sturdy block when you’re not using it and can be stored on your bike frame thanks to a handy mounting bracket-cum-holder. 

Once extended, the Kryptonite KryptoLok 685 Folding Lock offers lots of reach and can be manipulated through wheels of all shapes and sizes and around something else too, like a lamppost. The locking barrel is very nicely engineered and, as a whole, this is a super sturdy bike lock. 

Kryptonite’s 6/10 ‘moderate’ security rating claims it will withstand most bolt cutters and be ideal for suburban areas, but may eventually yield to serious theft attempts with tools such as an angle grinder.

Kryptonite KryptoLok 685 Folding Lock: Price and availability

The Kryptonite KryptoLok 685 Folding Lock is available to buy right now from all major cycle accessory specialists and online outlets, including Amazon, starting from $74.95 in the US, £50.74 in the UK, and AU$149.95 in Australia. 

One of the additional benefits of buying a Kryptonite cycle lock is its Key Safe program, which means you can register with the company and they can help replace any keys should you end up losing the originals.

Kryptonite Kryptolok 685 folding lock in packaging

(Image credit: Rob Clymo)

Kryptonite KryptoLok 685 Folding Lock: Design

  • 85cm lock reach
  • Heavy duty barrel lock
  • Fully foldable

The Kryptonite KryptoLok 685 Folding Lock is just that: a bike lock that is designed a little like a concertina. When it arrives in its packaging, the lock is condensed into a chunky block of alloy and steel weighing in at 1.31kg. Remove it from the packaging though and you can easily open up the Kryptonite KryptoLok 685 Folding Lock to reveal its full potential. The design is one of the main bonus factors, especially if you regularly need a little more freedom with your cycle lock.

Some bike likes, particularly those of the D-lock style, are often a little short on coverage, meaning they’re great for putting around a wheel and frame, but little else. The Kryptonite KryptoLok 685 Folding Lock on the other hand extends up to 85cm, thanks to its concertina design and this allows it to reach much further. This is hugely practical if you want to harness your bike to railings, a lamp post or, indeed, other bikes.

Kryptonite has done a great job with the locking barrel part of the design equation here too. It’s very chunky, there are two keys and the mechanism is both easy to access and works smoothly too. The 5cm-thick folding sections of the lock are top-notch quality too, although the hardened steel surface of the component pieces is less forgiving on bike frames than some other locks. It’s a factor that’s worth bearing in mind if you prize the paintwork on your bike or have a brand new cycle to fret about.

  • Design score: 3/5

Kryptonite KryptoLok 685 Folding Lock: Features

  • Collapses for storage
  • Mounting bracket included
  • Two-key barrel lock

One of the great things about locks in the Kryptonite range is that the lively yellow and black packaging always shows the security rating of the product. In the case of the Kryptonite KryptoLok 685 Folding Lock, it gets a 6/10, with a rating of '1' being a mild deterrant and '10' being as safe as houses, even for densely-populated urban areas. 

6/10 is classed as ‘moderate’, which means it’s more than adequate for everyday use in rural, suburban and most urban environments, but not be quite as useful if you’re planning on locking it up overnight in an area known for effective, well-armed bike thieves. 

The fold-out design is actually one of the key features of this lock, as it delivers a lot more flexibility in terms of reach, right up to 85cm. That aspect could also make it quite awkward for any cycle thief to get a grip on as the sections move around so easily. Granted, the lock would probably succumb to an angle grinder, but seems well-placed to fend off bolt cutters. 

The other key feature of the Kryptonite KryptoLok 685 Folding Lock is that it comes complete with a plastic mounting block, which can be fixed to your bike frame and acts like a holster for the lock when you’re on the go. It’s nicely made and will fit to a bike frame without causing harm to the paintwork and certainly less scratching than you’d get from simply harnessing the lock around your bike. 

A couple of keys for undoing the lock barrel are supplied as standard and Kryptonite has a Key Safe program, which means they can replace any that get lost following their registration process. A definite bonus!

  • Features score: 3/5

Kryptonite KryptoLok 685 Folding Lock: Performance

Kryptonite Kryptolok folding lock

(Image credit: Rob Clymo)
  • Positive locking performance
  • Extra reach is a real boon
  • No play in the multiple components

Using the Kryptonite KryptoLok 685 Folding Lock on a daily basis is easy enough, although initially it feels like a bit of a handful as you try and tame all of the connecting sections. These are connected with a steel rivet-style system, and thankfully there’s no play between the links. 

How they fare over time and with increased use will be interesting to see, as locks like this can have the habit of becoming a little loose over time. In fact, some of these concertina-style locks can become downright floppy with prolonged use, but so far, so good.

Once you’ve worked out the best way to snake the sections through your frame or wheels and, say, a lamppost the lock is easily joined up and locked thanks to that chunky barrel. The locking action feels good and solid, while the two keys are sizeable enough to you can keep then in a coat pocket or in a bag without them disappearing as can happen with some locks that come with dinky keys.

  • Performance score: 4/5

Kryptonite KryptoLok 685 Folding Lock: Buy it if...

You need some added flexibility
This lock extends up to 85cm and can be worked in and out of spokes, frames and lamp posts too. 

You’re after a mid-range model
This has Kryptonite’s own 6/10 security rating, which makes it a solid option for short-term cycle stops. 

You tend to lose keys
There’s a Key Safe program in operation with Kryptonite, which means if you register they can replace any misplaced keys. 

Kryptonite KryptoLok 685 Folding Lock: Don't buy it if...

You just need a simple D-lock
This is an extendable design, so the added bulk might be unnecessary for some cycle needs. 

You’re after a higher security bike lock solution
It’s a Kryptonite lock, so the design is great but only offers a 6/10 based on their own standards. 

Weight is an issue
This does come with a plastic mounting bracket for your frame as it’s a little chunky for a coat pocket or backpack.

 First reviewed December 2022 

Rob Clymo

Rob Clymo has been a tech journalist for more years than he can actually remember, having started out in the wacky world of print magazines before discovering the power of the internet. Since he's been all-digital he has run the Innovation channel during a few years at Microsoft as well as turning out regular news, reviews, features and other content for the likes of TechRadar, TechRadar Pro, Tom's Guide, Fit&Well, Gizmodo, Shortlist, Automotive Interiors World, Automotive Testing Technology International, Future of Transportation and Electric & Hybrid Vehicle Technology International. In the rare moments he's not working he's usually out and about on one of numerous e-bikes in his collection.