SIGTUNA Folding Bike Lock - Hardened Steel 8mm Fold-Up Heavy Duty Bike Lock with Easy Mounting, Secure Lock and Anti-Scratch Coating - Easily Keep Bike Secure and Paintwork Undamaged - Bicycle Lock

This lock is not terribly heavy so it can be attached to the bike and carried along without too much penalty. I think that it's very durable and very difficult to break. If a serious thief wanted to take the bike, there's no question that with the right tools this could be broken like almost any lock. However, I feel safe with this lock in the locations that I park the bike

I purchased this lock with very specific use cases in mind. I have a big, study u-lock, which I find heavy and hard to carry. It is also not necessary for everywhere I go - if all I need to do is a quick stop, it doesn't require a monster of a lock. With this new lock I wanted something versatile and convenient, for when I needed to leave the bike unattended in a busy area. Not looking for the highest form of security available, but rather something easy to keep on me at all times, lock and unlock.This Sigtuna folding lock fits the bill exactly. It isn't excessively heavy at < 2lbs, while feeling sturdy. It has this flexibility quality to it, allowing you to lock to virtually anywhere. The length is appropriate - longer than my u-lock, but not too long. The joints are very smooth, it's very easy to unfold and fold this lock. Contrary to some reviews, I didn't find any resistance in inserting or rotating the key - it feels very easy - maybe this has been improved.My favorite aspect of this lock, however, is how compact it folds and sits on the bike. Mine is mounted to the bottle mount and it stays absolutely still, no rattling, no noise.I am interested to know how it will hold over time, but I'm happy there is a warranty.

Little bit bulky, but what can you expect from interlocked metal plates XD. it's an overall good product, piece of mind my bike won't get stolen with this lock hanging off it, great deterrent.

I bought this to help me hang onto my new, expensive eBike. It's been a few weeks and I still have the bike, so, so far, so good.It's built very well, seems like it would be hard to cut through without setting off my bike alarm, and doesn't scuff up the bike's finish at all. It fits well in it's mount, which I have secured to the bike with the water bottle mounting bolts; there's no rattling about or anything like that. The mount itself also is rock solid.On the downside, it takes a bit of finagling to get the key into the hole for locking and unlocking. I always feel like I'm trying to lock-pick my way into a safe or something. I tried a little WD-40 in the lock hole, but it made little difference. Maybe it'll loosen up with time. Also, I wish it were just a *little* longer! One more folding section would make a world of difference. As it is, it's often hard to get the thing around a bike rack pipe and the down tube of the bike.Still, for the money, it's a good, solid piece of hardware.

I recently purchased the SIGTUNA Folding Bike Lock for my e-bike and have been thoroughly impressed with its performance. The hardened steel 8mm bars provide a sense of security that is essential in the city. Despite its heavy-duty construction, the lock is surprisingly compact when folded, making it easy to carry without adding bulk.Mounting the lock to my bike frame was straightforward, and it stays in place while riding without rattling. The locking mechanism operates smoothly, and the provided keys fit well, without the wiggle or stickiness sometimes experienced with other locks. I particularly appreciate the peace of mind that comes with the anti-theft design; it feels significantly more secure than a standard cable lock.Whether you have an electric bike or a regular city bike, this lock combines portability with strong theft protection, a balance that's hard to find. It's a small investment for ensuring your bike stays where you left it. Highly recommended!