Always secure your bike to a bike rack! If your bike is not secured to a solid object, all a thief has to do is pick it up and carry it away or toss it into a car trunk or van.
Use a chain at least 3/8" in diameter and a key lock with a 3/8" hardened shackle with heel and toe locking.
Pull up any slack in the chain and keep the lock as high off the ground as possible.
Put your lock through the tire and frame.
Consider the cost of replacing your bike when deciding how to protect it. If you have a $1,000 bike, you should spend more on your lock and chain than if your bike cost only $100. One rule of thumb: spend 10% of the cost (i.e. $100 bike - spend $10 on lock & chain).
Choose carefully where and how you park your bike. Choose well-lighted, public places. If you can, park your bike where you can see it.
Register your bike with the 麻豆传媒 Police Division, as this may help them recover it if it is stolen.
Report any suspicious activity, especially people seen loitering near bike racks, to 麻豆传媒 Police at 327-6231.