The 5 strongest bike locks
Whether you're a recreational cyclist or hardcore bike commuter, the strongest bike locks can let you feel more confident that when you leave your bike alone, it'll still be there when you get back. To help you find the right lock for your ride, I've rounded up a selection of some of the best options out there in terms of strength. Before you pick one out, however, there are several things to consider.
The first thing to know is that there's typically a weight-to-strength tradeoff with bike locks, so the stronger and more foolproof yours is, the more heavy and bulky it will likely be. For this particular roundup, most of the locks are fairly hefty but, in some cases, I included links to more lightweight alternatives for those who are willing to sacrifice a degree of strength.
As for the best types of bike locks, there are a handful of common options to consider: chain locks, U-locks, combination locks, folding locks. Chain locks are typically the toughest and can often withstand hacksaws and chisels, but that means they're also the heaviest so they may not be the best choice for every rider. U-locks are usually the next toughest choice, as they're capable of resisting hammers and chisels (thought not hacksaws). That said, the best ones are also rather heavy. And folding locks, though not quite as strong, can often be a more compact, lightweight option.
Regardless of which design you choose, keep in mind that no lock is completely impenetrable. On top of that, it won't be effective if you don't use it properly, so make sure you know how to lock your bike up correctly. Finally, keep in mind that sophisticated thieves can swipe quick-release seats and wheels, so you may also want to invest in a locking skewer set for added protection.
With all this in mind, read on for the strongest bike locks.
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1. The tried-and-true one
If what you're looking for is one of the absolute strongest, safest, and most secure options out there — without factoring in weight and size — this heavy-duty bike lock is the way to go. With rugged 15-millimeter round chain links constructed with hardened steel, it's exceptionally tough and strong. The steel shackle has a double deadbolt that can't be rotated, and it's resistant to tools like bolt cutters and levers. It comes with three stainless steel keys and an LED key fob.
Just note that this one weighs in at over 15 pounds, so if you're looking for something lightweight, this is not the lock for you.
One reviewer says: "Gives you the peace of mind that your bike is secure and safe. Totally recommend."
2. The heavy-duty U-lock
Constructed with a tough U-shaped piece that bolts four times into the body of the lock, this ABUS model is one of the best U-locks out there in terms of sheer strength. Significantly lighter than the previous lock, it weighs just over 3 pounds and is rated a 15/15 on the brand's security scale — the highest it goes.
With a 13-millimeter parabolic square shackle made from hardened steel, this lock has a double-bolting system that's extremely resistant to being picked, according to the brand, and it has a tough key cylinder and corrosion-resistant design. This lock comes with two keys, one of which boasts an LED automatic keyhole.
If you're looking for something more lightweight that's still quite strong, check out the similar ABUS Granit 640, which weighs under 2 pounds and has a 12/15 security level rating from the brand.
One reviewer says: "This is a very heavy duty lock. It definitely will be difficult for someone to cut through this twice, in order to steal our bikes. The fit and finish of the lock is impeccable."
3. The folding bike lock
This folding bike lock is one of the toughest and strongest of its kind. Designed to be lightweight and compact, it features 5-millimeter steel bars with strong saw-resistance, along with a convenient folding design. With a soft silicone covering to protect your bike from scratches, this lock is small, compact, and easy to toss in your backpack. Just note that due to its strength, it is one of the heavier folding locks on the market, weighing a little under 4 pounds. For a more lightweight alternative, check out the Foldylock Clipster.
One reviewer says: "The lock is amazing overall. I left my bike outside, overnight, locked up against a post for 12+ hours and came back to find it... THERE, which is all anyone can ask for. The lock is heavy and you can feel the difference when having it on/off the bike."
4. The combination chain lock
Built with 9-millimeter quadruple-sided 3T manganese steel chain links, this heavy-duty option from Kryptonite is one of the best combination bike locks out there. Rated a 6/10 on Kryptonite's security scale, it's among the tougher of the combination-style locks, with a flexible design and end link locking point to secure it in place. The five-digit combination gives you more than 100,000 possibilities for codes, and it has a weather-resistant nylon sleeve to spare your bike from scratches. At roughly 7 pounds, it's more than half the weight of the other Kryptonite lock on this list.
One reviewer says: "This is a heavy duty lock system. [...] I love the combo feature so I don't have to keep track of yet another key. And the 5 digits makes for a secure lock as long as you make sure to scramble the code when you lock up. This lock says 'don't even try'. I figure if someone is sophisticated enough to compromise this beast then I'll just replace the bike with insurance money. It would take a determined foe."
5. The budget lock set
With nearly 3,000 reviews on Amazon, this popular budget bike lock features 14-millimeter steel and a hexagonal PVC cover that's weather-resistant, and it comes with two keys, along with an easy mounting bracket. As a bonus, you'll also get an 18-centimeter cable to add an extra layer of protection. Altogether, both components weigh just 3.5 pounds, which is on the lighter end of this list.
One reviewer says: "This bike lock is the best one I have ever bought. It is perfect for my bike. [...] I feel comfortable leaving my bike anywhere now as long as I have this lock. The added cable comes in handy when I need to lock against large trees or bigger poles. The cable is extremely strong but also very flexible so you can wrap it around anything. [...] Absolutely would buy again for others in my family. LOVE this product."