Master Lock Black Bike Lock with Key, Standard Size U-Lock for Bicycles and Other Outdoor Equipment, Anti-Theft Lock for Bikes, 8320D

Great value for money, its quite wide and it fits perfectly for any type of bike stands, it's also quite heavy and strong, never had any issues with it

Incredible! Keeps my bike nice and secure.

Lock is functional, the length was just right for my 35mph e-scooter. The thickness was not that much hardly but it does the job. It comes with a two set of keys.Pros: Great for short trips, ideal for low crime areas but better safe than sorry type of person, easy to lock, affordable, sleek look.Cons: Not for long trips.

The U-lock feels solid and secure, and it does the job well when it comes to keeping my bike safe. However, after using it in the rain a few times, I noticed that it started to rust, especially around the keyhole and joints. That was a bit disappointing, as I expected better weather resistance. It’s still functional, but I now avoid leaving it outside in wet conditions. Decent lock overall, but not ideal if you need all-weather durability.

Fits my needs. Seems strong. Big enough to wrap around the bike and the rack. Cable is nice for fork/front tire. Key turns smooth every time.

This U-lock gives me real peace of mind when I leave my bike locked up downtown. It’s solid, well-made, and the included keys work smoothly. It fits through the frame and wheel easily, and I’ve had zero issues with rust or sticking. Just feels like a product that’s built to last.

These days, it's often about the keys; I don't know if any are able to put up much of a fight. Lockpickinglawyer is a popular inquiry (youtube). I owned two Kryptonite locks; keys with chiseled out rectangles at 90° length of key shank, last couple years. Both locks were picked multiple times, once they left bike in building, and took the lock. The previous Kryptonite key, (round) proved useless to an online order little tool, (about 10 seconds or something, same youtube, or a bic ball point pen ). Can any lock put up a decent fight? Are you concerned with the diameter of shackle?This u-lock does not have a thick shackle, but hardened steel, and make of serpentine key unseen, but I ordered with listed specs; intend to carry 2 U-locks. Stars given for standard rust free quality, specs at cost.

I recently bought the Master Lock 8170D U-Lock, and my experience has been a bit mixed. The lock feels sturdy and solid, providing a decent level of security for my bike. The 6-1/8 inch size is convenient, making it easy to lock up my bike frame and wheel to most bike racks. The black color is sleek and blends in well with my bike’s aesthetic.However, I've had some issues with the locking mechanism. It can be a bit finicky, requiring multiple tries to get it to lock or unlock. This is frustrating, especially when I'm in a hurry. The keys also feel a bit flimsy, which raises concerns about long-term durability.While the Master Lock 8170D provides basic security and is easy to carry around, the unreliable locking mechanism is a downside. It’s a decent lock for low-risk areas, but I would recommend looking for a more reliable option if you need maximum security. Three stars!