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It’s better to be safe than sorry, so while you may have a preference between chain locks and U-locks as far as bike protection is concerned, ideally you should equip your bicycle with one of each when leaving it unattended.
We’ll look at the main chain lock benefits and U-lock advantages below, as well as a ‘U-lock vs chain lock’ comparison (including which the better choice for commuters is), and the current stand-outs on the market in each category:
Chain Lock Pros + Cons
A chain lock for bike riders is comprised of hardened steel links, often within a protective nylon sleeve, and the lock itself, which can become part of the chain or a separate padlock entirely.
Here are the biggest chain lock advantages and pitfalls:
|Length and flexibility makes them more versatile – will suit a wider range of bikes
|Can be heaving than U-locks yet offer similar level of security
|Excellent visual detterent
|Can be awkward to carry
|Can be wrapped around seat post fairly easily – none of the difficulties that U-lock frame mounts pose, for example
|Harder to get a strong grip of when using an axle grinder
|Tougher, can withstand more attacks – can be jacked/leverage open, harder to cut with power tools
|Can be difficult to keep in place
U-Locks Pros + Cons
U-locks are a solid metal shackle with a removable cross bar. They loop around your bike frame and a post (e.g. railing, bike rack) to secure your bicycle.
Essentially giant padlocks, they also usually come with a cable to loop through your quick-release wheels.
Let’s look at the main U-lock benefits and drawbacks:
|Similar level of toughness and protection to chains, but lighter and cheaper
|Can be difficult to loop through some bike frames
|Stiff shape makes them easier to fasten around your bike
|Stiff shape can also make carrying U-locks harder (albeit still easier to carry than chains)
|Great visual deterrent
|Smaller size can make them harder to fit around larger posts (e.g. lampposts)
|U-locks come with optional additional cable
Is There a Difference Between U-Locks and D-Locks?
No. U-locks are so called because, from a certain angle, they form the shape of the letter U. Turn them on their side and they will look like the letter D, hence why they are also called a D-lock.
That’s why the same type of lock has two commonly-used names, so don’t be confused if you’re left wondering what separates the Us from the Ds.
Are Chain Locks Better Than U-Locks?
It really all depends on what you want from your bike lock. If you want value for money or ease of use, then U-locks probably trump chains in those departments.
But if you prefer a sturdier, tougher lock which provides greater versatility and perhaps acts as a stronger visual deterrent, chains are the better choice for you. Even if you don’t mind paying that little bit more of a premium.
So, What Type of Bike Lock is Best for Commuters?
Given commuters may be working on tighter budgets and time constraints, the U-locks may be their first port of call given you get much the same level of protection for a fraction of the cost of chains.
Plus, they’re generally quicker and easier to fasten around your bike, and won’t weigh you down on your cycle to work as a heftier, bulkier chain lock might.
Are chain locks good for commuters, too? Undoubtedly. Their tougher build and greater flexibility would still render them a great choice for cycling to and from work. But in this scenario, we’d say U-locks just have the edge.