Types of bike locks

When buying a bicycle, one of the most important things to purchase alongside it is a quality bike lock (x2). There are many types and brands of locks available on today’s market, all offering differing levels of protection against a thief. If you’re new to cycling or bicycle security, it can be confusing. Sadly, there are thousands of stolen bikes every year so it’s very important to make the right choice.

Whilst this guide gives you a general overview of the different types of locks on the market, different brands and models of the same type of lock offer different levels of protection. So to measure and compare the quality and strength of locks, always go by the ‘Sold Secure’ rating. If the bike lock does not have a Sold Secure rating on the product packaging, don’t buy it. There are four different ratings: bronze, silver, gold and diamond. Diamond offers the highest level of protection (we would only recommend using gold, or diamond, standard bike locks in London). Also note that cycle insurance companies will specify what Sold Secure rated bike lock you should use for your policy to be valid.


The D-lock is also commonly known as a U-lock. These shackle locks have been around since the 1970’s and are essentially a giant padlock. They can vary in size, weight and strength.


  • A proven design
  • Generally resistant to bolt cutters (depending on the quality)
  • Generally lighter than the majority of chain locks
  • Generally resistant to picking, drilling and leverage attacks
  • Generally cheaper to comparable quality, Sold Secure chain locks
  • Available at every Sold Secure rating level (bronze, silver, gold and diamond)
  • Most come with a bracket for mounting to the bicycle frame
  • Generally heavy and difficult to carry around
  • Sometimes based on the size (if small) and the flexibility, they can be awkward to loop around non-standard or bigger stands/objects

Lock buying tip!
When locking with a D-lock it’s important to ensure you have a tight fit (reduce the space) to prevent thieves using leverage style attacks. It’s good practice to use two slightly different types of locks, for example one chain lock and one D-lock.

Chain Lock

A chain lock consists of hardened metal links creating the chain. The chain is locked with a padlock. The links and chains as a whole vary in size, weight and strength. Usually the more secure chain locks are heavier, but are less portable.  Often the links are covered with a plastic sleeve to protect the chain and bike.

Chain lock

  • Visual detterent
  • Generally can be used to easily secure to a wide a variety of objects/stands, due to the size and flexibility
  • Can be awkward for a thief to use power cutting tools, due to the moveable nature of the links
  • Available at every Sold Secure rating level (bronze, silver, gold and diamond)
  • Generally bulky and heavy
  • Most (not all) can be cut with bolt croppers (depending on quality and the size of the links)
  • If not careful, the lock can be loosely fitted between the bike and the object/stand that exposes gaps for  leverage or cutting style attacks
  • If not careful and if the chain lock has exposed chain links (no protective or worn plastic sleeve) then there is a risk of damaging the bike paint work

Lock buying tip!
If a thief is determined to break a bike lock, they often will. So it’s your job to make it less attractive and more difficult for them. Including having the right locking technique and choosing the right location to leave and lock the bike. Whatever you can’t secure, take with you. Bike locks can’t keep everything safe; consider changing quick release bolts to security bolts that can’t be undone with an Allen key (they require a special key).

Cable Lock

Cable locks are lightweight bike locks that can be transported around pretty easily with minimal fuss. Like chain locks, they’re also flexible meaning they can be secured to lots of objects.

You may also see combo locks available on the market. These locks are simply cable locks which are unlocked with a combination, rather than a key.

Cable lock

  • Light and easy to carry
  • Flexible
  • Visual/basic deterrent in low risk areas
  • Can be used as an extra lock to help protect bike parts
  • Should not be used as a primary lock
  • Should not be used in medium or high risk areas
  • Very weak, at risk from all types of attack methods
  • Can be cut within seconds by bolt croppers
  • Not available at every Sold Secure rating level (only bronze)
  • Even if the cable lock looks tough and thick, the internal cable‘s are usually a lot thinner and still very easily cut

Lock Buying Tip! 
When you are shopping for your bike lock, focus your search on bike locks that have been rated by Sold Secure. Buying a Sold Secure rated lock for your bike gives you peace of mind that the lock has been rigorously tested and also means insurers will most likely pay out (other factors are at play, so read the small print of any policy) in the event of a theft taking place.

Folding lock

As per the name they are folding and have a very compact design. Most come with a bracket for your bike frame for transporting.

Folding lock

  • Easy to carry, if mounted on the bike frame
  • Generally can be used to easily secure to a wide a variety of objects/stands, due to the size
  • Usually lighter than chain and D-locks
  • Available at the top end of the Sold Secure rating level (gold)
  • Not many manufactures offer folding locks, so the choice is limited (but there are many new start-ups in the bicycle security industry developing constantly)
  • Have not been on the market as long as D-locks
Lock Buying Tip!
It is wise to take good care of your lock to prevent jamming. Sometimes dirt or other elements can get into the mechanism causing a jam. To maintain the lock always read the manufacturers guidelines, but consider occasionally checking the key hole, ensuring if it has a flap that it is closed and there is no dirt inside. A little lubricate can be used or a water displacer spray for maintenance (or if the bike lock is actually jammed).  

Ground Anchor

Ground anchors are drilled into concrete, be that in a garage or another location to offer a secure anchor point to attach a bike lock to. A high percentage of thefts occur at home, so it’s important to consider an anchor (wall anchors also exist) if you have a garage or shed, as you are unlikely to have another secure object to lock your bike lock too. Anchors do vary in security rating, just like locks.

Bike ground anchor

  • Rated by Sold Secure, so it’s possible to see the standard (diamond, gold, silver and bronze)
  • Provides an effective locking point
  • Requires basic DIY skills to fit a ground anchor and some spare time
  • Needs a suitable location (close to the bike) and appropriate flooring to drill the bolts into. As sheds rarely have concrete floors, this lowers the options.
  • Can be awkward to lock the bike lock to (usually best used with long chain locks)

Lock Buying Tip!
Whichever lock you opt for you must make sure it is suitable for your needs and the locations that the bike is likely to be secured in. Some areas will pose a higher theft risk than others. You’re always best securing your bike with a lock in a location that’s covered by CCTV. Also, consider locking your bike up where other bikes have been secured.


Your lock is only as effective as what you’re securing your lock to. If the object isn’t sturdy or stable, a thief could end up taking your bike and your lock.  No bike lock can guarantee your bike’s safety, but proper use of locks and technique can greatly reduce the risk of bike theft.  Never use a cable lock as a primary lock. When in doubt, discuss your security options with a reputable local bike shop who can advise based on your location, value of your bike and insurance requirements.

Read our guide on how to lock your bike.