Types of Locks 

While there are many different lock styles and combinations on the market, the three-most popular styles are: i) cable locks, ii) chain--link locks, and iii) u-locks. Unfortunately, not all locks are created equal, and some are more prone to being breached than others, namely the exclusive use of a cable lock. 

How Can I Tell How Secure A Lock Is?

Trying to understand the lack of cohesion between the seemingly arbitrary scales which vary from brand-to-brand can feel daunting and confusing. Luckily, an organization in the U.K has developed a standardized form of measurement to classify the security of a lock. The assigned level is determined by examining how the lock's construction, materials used, and design contribute to a lengthening of efforts to breach the lock's security (or how easy it is to break a lock).There are four main categories identified and examined within a "solid secure" rating, which are,  i) bronze, ii), iii) gold, and iv) diamond; these levels coincide in ascending order the degree to which they offer security.  Thus, any lock that carries a solid secure verified rating has been extensively tested which provides the consumer a transparent guide to selecting the most appropriate lock for its intended use. The following is how the classification system is categorized. 

Lock Recommendations According to Solid Secure Ratings (or better)

How Do I Lock My Bike Properly?

Whenever you leave you bike for any period of time, it is essential to make sure that when you go to lock it up that you secure the frame to an affixed object (such as a bike rack) that  does not move. Ideally, a wheel and the frame are secured within the u-lock and an additional lock (if the bike has quick release skewers) are used to ensure you "cover all your bases" in order to prevent a potential theft. 

How not to lock your bike When locking your bike, you would want to ensure the more secure U-lock is connected through the frame to the affixed object (bike rack) and then supplemented with a cable lock. In this example, someone could easily take a pair of wire cutters, cut the existing cable and take off with the bike as the u-lock is not affixed to anything static.

How to lock your bike Here the u-lock connects the frame and rear wheel to the affixed object. If you are parking your bike in a higher-risk area, connecting a supplementary lock ensures your bike is more secure. If your lock cannot reach from rear wheel to front wheel, you can always carefully take the front wheel off and loop your supplementary lock through it so that your whole bike is secured.

Extras:

• If the lock you have purchased, or plan on purchasing has a set of keys with a serial number, write it down or take a photo of it and send it to yourself via email/ upload it in the cloud. This is key, as in the event the pair of keys that once came with the lock are misplaced, you are able to order a new pair. For example, here is the link to order new keys through ABUS. 
• If you are concerned about your wheel(s) being stolen, ABUS makes a product called the "Nutfix" which are wheel locks designed to prevent your wheels and seatpost being stolen. That product can be found here.
• Ensure that you have the serial number of your bike in your personal records (if possible). This is key in identifying the re-surfacing of your bike in the event it is stolen. More information about where you can find your serial number and additional security measures can be found here.