Have an old bike combination lock that you can't remember the code for? If it's a simply four-digit cable lock, you can easily figure out the combination with a quick peck-and-go method. Best of all, this technique doesn't require any tools or special know-how, and let's you reuse the cable lock again versus just damaging it with bolt cutters. All you need is a bit of patience and you'll have your figure out your combo in no time.