SIGTUNA 16mm Heavy Duty Bike Lock

SIGTUNA 16mm Heavy Duty Bike Lock

When it comes to bike theft, there is a growing problem, and there just doesn’t seem to be enough police to deal with it. Bike theft is getting worse in every city in the United States and even around the world. The penalties aren’t harsh enough and even good locks seem no more a barrier to thieves than a thin cable lock you might find at a dollar store.

But there are a few bike locks out there that actually do the job they were created for, and a short list of companies that work very hard to make sure that if you buy their lock, your chances of bike theft are slim to none. One of those is this SIGTUNA lock – one of my favorites and the one I use myself on my bike.

SIGTUNA 16mm Heavy Duty Bike Lock on a bike

Introduction To The SIGTUNA 16mm Heavy Duty Bike Lock

This SIGTUNA bike lock is one of the top rated locks for several reasons, but one of the main ones is the design and construction of the steel. This is 16mm reinforced steel that will stand up to cutting, pushing with a lever and just about anything else except for perhaps an acetylene torch.

This lock comes with both a U-bolt (sometimes called a D-bolt) lock as well as an extremely strong cable and it gives you enough length to protect your bike like the experts recommend – by looping it through the frame and then the tires if you have enough room. SIGTUNA is one of the top brands when it comes to bike locks, and many security experts compare them to the well-known Kryptonite brand.

This lock comes with a 100% money-back-guarantee if you aren’t completely satisfied by it, and that makes it a very good purchase. Let’s look at the features that come with this lock.

SIGTUNA 16mm Heavy Duty Bike Locks Dimensions


  • 16mm hardened steel U-Bolt lock
  • 1200mm flex cable for added security at no extra cost
  • ​100% no-questions-asked guarantee
  • ​Free shipping with Amazon Prime membership
  • ​Double bolt secures both sides of the lock to the crossbar
  • ​Mounting bracket makes locking up your bike incredibly fast
  • Extremely durable and tested to above specifications

My Results

What originally got my attention with this lock was the mounting bracket which I found was absolutely convenient and easy to install. But once the lock was mounted I also found it to be one of the most secure locks I had ever come across.

Carrying SIGTUNA 16mm Heavy Duty Bike Lock on a Bike

What really makes this lock different is the way that it hooks up to whatever you are anchoring it to, which leaves very little room for thieves to work their dark little deeds. This lock does what it says it will do and has protected my bike for more than six months now, even though I have known several people that have had their bikes stolen – neighbors, friends and the like.

What Others Say

The testimonials on this lock really showcase just how fine the design and construction is. I want to take a look at one testimonial in particular, which was posted when I first decided to get this lock and it helped convince me that this was the right lock for my purposes.

That review was from D. Jones who said that this lock was as good as the Kryptonite one (which I had heard of) at half the price. What convinced me was that he (or she) took the time to come back and post an update to the review later and it was still a glowing recommendation for this lock.

Insider Information

One of the things that I took from D. Jones’ review was that a little WD-40 does wonders in keeping the lock working properly. Unfortunately, it is not weatherproof so it does get a little stiff when it gets cold but if you spray WD-40 once a month or so you will have no problems turning the key and opening the lock.

SIGTUNA 16mm Heavy Duty Bike Locks 1200mm braided Steel Flex Cable

Buying Advice

There are three things that I would make you aware of when it comes to buying advice. First, at the time of this review, the lock is less than half what I paid for it, so I would get it right away if I were you. Also, you can get free shipping with a trial (and they do monthly now) of Amazon Prime.

Finally, you don’t need the mounting bracket that is listed on the “Recommended Products” list because it already comes with everything you need to mount this lock. The fact that it is in the “also bought” section means that a lot of people must have thought they needed it and bought it, but mine came with the brackets and all of the bits and bobs that were required for installation – minus the tools of course.


So, the SIGTUNA U-Lock is one of the best locks on the market, comparable with the big names like Kryptonite and working even better than some of those locks because of the mounting bracket that makes this lock almost impossible to get leverage against to break or cut.

With all of the features that this comes with and how well it protects your bike, getting it should be a no-brainer, but it is more than half off right now and you can even get free shipping if you sign up for a trial of Amazon Prime.


My Verdict

I definitely recommend this lock. It has been one of my favorites and the only one that I see myself using in the coming months and years.

They may come out with a better lock at some point, but so far this one is in the top few on the market right now and it is priced much lower than you’d expect for such a solid security item. I definitely would endorse this as the lock you should get for your bike.

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