There are a number of factors to consider, for example, the age of your child will determine their ability to use the lock. Some other factors to account for are the weight of the product and its convenience. In terms of security, the style is dependant upon your goal. For example, considering removable tires, you may want a chain/coil lock. These locks allow your child to lock up their whole bike. And consider each lock’s susceptibility to tampering. U locks, for example, have more vulnerability to the use of tools such as a crowbar.