The Master Lock Chain with Mini U-Lock offers more flexibility than a regular U-lock, with its 90cm chain handy for locking up your front wheel as well as your frame, or for wrapping around things a D-lock wouldn’t. Unfortunately, despite featuring 10mm diameter hardened steel links, it was the only lock in our recent round-up that failed to stand up to some 600mm bolt croppers.
There were 77,148 reported bike thefts in England and Wales in 2024 according to CrimeRate, and these figures are probably lower than the actual rate because many stolen bikes go unreported, so a half-decent lock that can either put a thief off or slow them down is a must if you leave your bike away from home.
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This Master Lock Chain and Mini U-Lock is a heavyweight setup that would have once been reserved for motorcycles. It has been given a Silver rating by Sold Secure, a security testing and approval organisation based here in the UK.
Master Lock Chain
The 90cm chain makes it easy to lock your bike to something secure, such as a bike rack or lamppost. I have long preferred locks and chains over a U-lock because of the flexibility they offer, meaning I can secure both the frame and front wheel when I need to leave my bike somewhere.
This Master Lock uses burly 10mm hardened steel chain links, with a nylon cover to prevent scratching. This is great in theory but I found I needed to be careful because of the weight of the chain. It can hit your frame hard and potentially cause damage if you’re not careful. I use similar locks at home in my garage to chain my bikes together, several of which are carbon, so I’m aware of using heavy chain locks carefully.
Mini U-Lock
The plastic-covered mini U-lock part that locks the chain ends together features a 14mm diameter shackle that is, once again, made of hardened steel. This is designed to increase resistance to cutting and sawing simply because of the bigger diameter.
In terms of dimensions, the interior diameter of this mini U is 42mm, while it measures 48mm in height from the top of the barrel locking mechanism.
Master Lock says the high-security disc cylinder prevents picking, and the dual locking levers provide resistance against prying and hammering. The addition of a rotating key cover to keep the rain out is useful, especially if you leave bikes outside whatever the weather.
I was pleased to see it comes with four keys. This meant I could divide them among several keyrings and have a standalone for when I’m keeping things simple.
Weight
At just over 2.3kg the Master Lock is quite heavy compared with most half-decent bike locks, but it’s also more flexible to carry than a D-lock. I either stuck it in a backpack or over my shoulder and across my chest when I didn’t need to carry a bag. Bigger peeps might struggle with the latter.
Real world use
In day-to-day use, the Master Lock does a solid job. I particularly like the flexibility it offers when it comes to locking my bike – having 90cm of chain to play with meant I was never struggling to lock my bike to something solid.
It’s an easy lock to use, if not as quick to secure as a chain that has a built-in lock. This didn’t bother me, and I was happy to take a few seconds if this meant potentially more security.
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I also like that the nylon cover is riveted in place so it doesn’t slide up the lock or come off when you open the mini U-lock.
Security
A Sold Secure Silver rating sounds good, but how secure is it really?
The lock formed part of the recent road.cc round-up of locks that were put to the test by Dodgy Dave and his trusty bolt cutters.
These 600mm bolt cutters were a readily available model from one of the big brands, nothing specialist or unusual, and a size that a thief could conceal and carry about relatively easily. Dave used new bolt-cutter jaws for each lock, and was given up to a minute to try to cut through the lock, recording the time of its resistance.
Unfortunately, the Master Lock Chain with Mini U-Lock was the only one in the road.cc round-up that didn’t resist the bolt cutters within the 60-second time limit. (With some of the D-locks with cables, Dave cut through the cable but couldn’t cut through the D-lock.) He managed to cut through the Master Lock in 41 seconds. Any lock that didn’t resist the bolt cutters for a minute wasn’t put through to the angle grinder test, so I don’t know how well it would it have stood up to this.
Value & conclusion
The fact that this lock was cut through in under a minute might set alarm bells ringing, and while you would expect more expensive locks to resist this, there were others – some cheaper – that held up for longer. For example, the Halfords 23cm D Lock fought off the bolt cutters and resisted Dave’s angle grinder for 33 seconds, and costs just £30.
If you don’t need the flexibility of the chain, a far better buy in Master Lock’s range is its £49.99 U-Lock. This managed to beat Dave’s bolt croppers and resisted his angle grinder for 42 seconds. Or, for a penny more, the Halfords Advanced 23cm D Lock lasted an impressive 94 seconds against the angle grinder.
At £39.99 this lock is a lot cheaper than some – the most expensive lock in the round-up was £289.99! – and while it doesn’t offer the most security, it does look bulky and should act as a deterrent, so I think it’s a decent balance of cost and flexibility. If you’re only locking your bike for a quick shop or in the garage at night, it should do the job.
Ultimately, though, if you could manage without the flexibility of the chain, I would suggest giving this lock a miss and going for the Master Lock U-Lock or Halfords Advanced 23cm D lock for an extra tenner.
Right to reply
We put Ian’s findings to Master Lock, to give the company the right to reply:
“At Master Lock, we strive to offer a wide range of security solutions tailored to different needs, environments, and budgets. Our product portfolio includes locks designed for basic deterrence as well as high-security models certified to rigorous standards.
“The Chain with Mini U-Lock is positioned as a versatile solution, ideal for medium-risk situations. The Chain with Mini U-lock passes every year the quality and performance tests of the renowned body of certification, Sold Secure. The Chain with Mini U-Lock is certified Pedal Cycle Silver and guarantees a medium level of security. However, for users seeking enhanced protection, we strongly recommend the Master Lock 8195EURDPRO, a U-Lock that is certified, by Sold Secure, Pedal Cycle Gold. This model offers significantly greater resistance to common attack methods, including bolt cutters, and is available at a comparable price point.
“We believe this alternative better meets the expectations of users prioritizing maximum security and would be a more suitable reference point in the context of this review.”
Verdict
Solid-looking deterrent that offers flexibility in use but can be cut through with the right tools in under a minute
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road.cc test report
Make and model: Master Lock Chain with Mini U-Lock
Size tested: 10mm x 90cm
Tell us what the product is for and who it’s aimed at. What do the manufacturers say about it? How does that compare to your own feelings about it?
The Master Lock Chain with Mini U-Lock is aimed at those who want solid looking security without a massive outlay.
Master Lock says: “The Master Lock No. 8234 Bike Lock Chain with Mini U-Lock is 3ft (90cm) long and features 10mm diameter hardened steel links, offering resistance to cutting and sawing. The nylon sleeve provides protection against scratching. The mini U-Lock features a 3-1/2in hardened steel body for maximum strength and durability, with a 14mm diameter shackle made of hardened steel to resist cutting and sawing. The high-security disc cylinder is designed to prevent picking, while the dual locking levers enhance resistance against prying and hammering. Backed by the Limited Lifetime Warranty, this product offers peace of mind from a brand you can trust.”
Tell us some more about the technical aspects of the product?
Master Lock lists these features:
Hardened steel chain resists cutting, sawing and prying
Nylon cover prevents from scratching
Hardened steel mini U lock
Disc cylinder for a better security against picking
Double locking shackle for maximum pry resistance
Vinyl covered body and shackle prevents scratching
Silver Sold Secure approved
It is well built and finished.
While it’s not the most secure lock available, it offers some positive credentials and acts as a deterrent.
Components of the lock are durable, but ultimately it doesn’t resist bolt cutters.
It depends on whether you see weight as added security or a pain to carry. I think it provides a decent balance.
It’s not the most comfortable when worn over the shoulder, and bigger riders will struggle to wear it.
The Master Lock is a burly hardened steel lock that will act as a deterrent. Features such as the riveted cover, plastic cover lock and keyhole cover are useful additions, but the fact that it can be cut with bolt croppers in under a minute reduces its overall value considerably – you can buy cheaper locks that offer better security.
Tell us how the product performed overall when used for its designed purpose
It’s a flexible and easy-to-use heavier weight lock, but unfortunately it can be cut through quickly with the right tools.
Tell us what you particularly liked about the product
The chain style makes it flexible in application and Master Lock has covered all the small things like the riveted chain sleeve and keyhole cover.
Tell us what you particularly disliked about the product
That it can be cut through in under a minute with the right tools.
How does the price compare to that of similar products in the market, including ones recently tested on road.cc?
In our test the Halfords 23cm D lock offers better security for less money (£30). The Master Lock U-Lock is a little more expensive at £49.99 but beat the bolt croppers, as did the Halfords Advanced 23cm D lock at £50, though both were cut with an angle grinder. For full security and locks that resist the grinder, the Litelok X1 (£149.99) is the cheapest on test that beat both cutters.
Did you enjoy using the product? Yes
Would you consider buying the product? No
Would you recommend the product to a friend? No
Use this box to explain your overall score
There are pleasing aspects to the Master Lock Chain with Mini U-Lock – it’s user friendly and burly looking, and the chain style offers more flexibility than a regular D-lock when it comes to locking your frame and a wheel to something. Unfortunately, it can be cut through with bolt croppers in under a minute, so if security is your number one priority, you’ll want to look elsewhere.
About the tester
Age: 54 Height: 170 Weight: 63
I usually ride: My best bike is:
I’ve been riding for: Under 5 years I ride: Every day I would class myself as: Novice
I regularly do the following types of riding:
1 thought on “Master Lock Chain with Mini U-Lock”
I’ve got this Burg-Wachter
I’ve got this Burg-Wachter 12mm chain and lock, at £50 it’s only slightly more expensive and it’s rated Sold Secure Diamond.