Reddit reviews Wordlock CL-422-BK 4-Dial Cable Combination Lock, Black, 6-Feet

/r/bicycling will be very happy to help you with this if you decide you want information. Here's the short version:

Locks aren't guarantees, they are deterrents. You just have to make your bike not worth stealing. Whenever possible, lock your bike in an area with plenty of pedestrian traffic, and where other bikes are locked.

Cable locks (example) are weak. They are for keeping somebody from walking away with your bike. If a thief has come to steal bikes, the thief will get this one, no sweat.

If you need something long like that, you can get a lock and chain (example) but be sure it's intended for use as a bike lock. Ordinary chain from a hardware store is too easily cut. This method is heavy and bulky, but it works.

My recommendation, to keep things affordable, simple, and convenient, is to buy a good U-lock (example). Kryptonite and On-Guard are popular, reliable brands, but there are others.

Most importantly, make sure you lock your frame to the bike rack. If you don't lock the frame, the battle is lost. Wheels are easily stolen, so lock these up as much as possible. If I'm being quick about it, I pass the U-Lock through the frame and rear wheel as well as the bike rack (the rear wheel is more valuable), but the front wheel can be detached to lock with the frame and rear wheel using the same lock.

You can look into locking skewers and such to protect your wheels and seat, but the priority is to use a good, strong lock to lock your frame and rear wheel to a highly visible bike rack. Also, keep a photo and detailed description of your bike WITH YOUR SERIAL NUMBER so that if anything happens, you can file a police report.

OP doesn't need a "good" lock. he needs a fucking lock that will prevent it from being stolen easily.

You only need a GOOD lock if you have a GOOD bike. I spent $100 on my last bike. I bought a lock for about $7 at walmart that held it secure for years.