I've been using this lock since it came out and it's now a staple on three bikes in the household. It's hands down the heaviest u-lock I've used and it's a trade off since it's the most durable. I've had two attempted thefts thwarted and have come out to see other cut locks without bikes and still see mine there.The mount onto the bike makes it a lot less weight to carry which is nice but if you're leaving your bike while out in a city (even a safe one like Toronto) this is the lock to get!

Easily the best U lock available today. The Abus 540 is noticeably lighter than it's biggest competitor, Kryptonite, yet continues to offer the same, if not higher, level of security. As well as utilising hardened steel, the lock features a dual-sided locking system, which prevents thieves from taking advantage of a massive weakness in many locks. Locks which only have mechanisms on one side can be warped and bent, allowing thieves around even the sturdiest of mechanisms.The Abus 540 meets gold standard specifications, which are often required by insurance companies. While you'll likely spend a little bit more for this lock, it's certainly worth it. At the end of the day, examine your needs, the weight you're willing to carry, and how much your bike is worth to you.

This item looks strong, but truly isn't. I thought this U lock was sturdy and a good anti-theft deterrent given its weight and intimidating looks. Sadly, a thief cut this lock open and stole my e-bike attached to it. I would invest in another lock outside of this one. Learn from my loss!