Buying a lock for a bike can be challenging. The two most common choices available in the market are the U-lock and the chain lock.
The U-lock is called so, because it looks like the letter U in the English alphabet. The working is simple, the length forming the ‘U’ slides around what is to be secured and is finally held by a lock. The prongs of the U-lock could be slid in between the spokes in the wheels, thus securing the wheel to the body of the ride. One would need to a key to unlock the assembly. And also, these come in various colors, sizes and prices. Bicyclists prefer these locks because these are easy to use. But these locks are neither light weight and nor economical. A sturdy lock may weigh around 2-3 lbs, and will cost about $50-$200 on the leading online stores. The quality of the lock is determined by the thickness of the shaft and the metal in the shaft, and also the locking assembly. These locks, however, are not meant to be used for purposes other than securing motor bikes and bicycles. If using with a bicycle or a motorbike the lock is generally clamped to the frame or the suspension fork. Despite its simplicity the U lock is limited to be used with only one bicycle (or motor bike).
Whereas, the chain-lock is nothing but a chain held by a lock at its ends. And like every other lock this one comes with a key too. The chain is put around the body of the bicycle, motorbike (or anything else that could be lied with the chain). The advantage with this type is its simplicity, flexibility and cost. This lock could be used for multiple applications like securing bicycles and motorbikes, securing suitcases and trunks. Furthermore, theses could be used to tie around lamp posts, fences, gates. The flexibility comes from the uses this product may have. One can buy a good chain lock for $20-$50 online. The price is determined by the chain quality and the quality of the lock assembly, and also the interfacing of the lock with the chain. Due to the simplicity of the chain-lock it is easier to manufacture at a more economical price. The required weight of the lock and chain is determined by the application. A 0.5lbs set may secure a standard bicycle tied to a lamp post. Whereas a longer and heavier chain-lock will be needed to secure a heavy cruiser motor bike. The chain-lock provides adequate security to anything that it could be used with. However, the limitation is its portability when not used with bikes. Also, they look clumsy as the only way to store them is by coiling.
From a users point of view, it is a choice between the neat and finished looks of the U-lock keeping in mind the higher weight and the price, and the flexibility in using the cheaper chain-lock which is not as good looking. In the battle of the locks, the chain-lock may have a slight advantage over the U-lock owing to the former’s value for money.