Our cycling experts have spent years testing an extensive range of bikes, gear, and accessories. To identify the best bike lock available, we thoroughly reviewed the research and leveraged our expertise on different lock types and what cyclists need from them. We then searched the market for top-performing and popular models from more than a dozen brands. After purchasing the leading contenders, we put them into service guarding our two-wheelers. We spent several months with these locks, securing bikes to racks, poles, trees, fences, and posts through countless lock-and-unlock cycles. We also installed each mounting system repeatedly to assess ease of use. To gather diverse perspectives, we distributed the locks to fellow cyclists for additional feedback.
We evaluated each lock across four performance metrics, each weighted by importance. Security carried the most weight at 40% of the overall score. While security is fundamental to any bike lock, it doesn't account for how the added weight affects your back and legs during long rides, or the frustration of wrestling with a lock in harsh weather. That's why we also tested portability (25%), ease of use (20%), and versatility (15%). Here's how we measured each category.
Security
We began by reviewing security ratings from independent agencies such as Sold Secure and Foundation ART, which evaluate each lock's structural integrity and susceptibility to compromise. While we didn't treat these ratings as definitive, they provided a valuable starting point for our assessment.
Our final test—conducted at the end of the testing period for obvious reasons—involved systematically destroying every lock. After identifying each model's weak points, we began with inexpensive hand tools commonly used by bike thieves: cable cutters, diagonals, and a three-pound hammer. These tools are inexpensive, easy to carry, and conceal. Next, we escalated to larger, more destructive implements also favored by thieves: 24" bolt cutters and a 12" hacksaw. For locks that resisted hand tools, we turned to power tools. Using a powered angle grinder with a cut-off wheel, we timed how long it took to break through each lock.
We conducted all tests under “ideal” theft conditions, securing locks in vises to eliminate movement and eliminate variables such as position and angle. This approach allowed us to evaluate the raw strength of each lock's materials while keeping our testers as safe as possible. In real-world use, proper locking techniques—such as positioning the keyhole downward and minimizing empty space within a U-lock—can significantly increase your bike's security.
Ease of Transport
We weighed each lock to establish baseline data for this metric. Since frame mounts are optional and vary by only a few ounces, we excluded them from our measurements. Beyond weight, we evaluated how easily each lock could be carried on your body or in a pannier, jersey pocket, backpack, or messenger bag. For locks with frame mounts, we tested their compatibility with different bikes and mounting positions, deducting points for any that rubbed against the legs, interfered with pedaling, or rattled during rides.
Ease of Use
A lock's ease of use directly affects whether you'll actually use it consistently. We repeatedly opened and closed each model to identify sticky mechanisms or smooth operation. Our testers secured locks to various bike racks and fixed structures to evaluate their versatility across different lockup points. We examined features such as keyhole covers, keys with integrated lights, and key designs to determine which were genuinely helpful and which were merely gimmicky. We also assessed the simplicity of frame mount installation.
Versatility
To evaluate versatility, we tested how much of a bike each lock could secure. Some models only accommodate the frame and one wheel, while others can secure the saddle, both wheels, and the frame to a fixed structure. We removed the front wheel and positioned it alongside the rear wheel to test whether both could be locked together. We also tested across different bike types and sizes—from slender road bikes with narrow tires to sturdy mountain bike frames (yes, we've tested many!) with wide tires. Locks that secured more bike components scored higher. Additionally, we evaluated how well each lock worked for securing other valuables like dirt bikes, motorcycles, bike cargo trailers, and equipment stored in garages or sheds.
