Moped & Bicycle Locksmith
Bicycle lock types and our recommendations
Cable Locks
These locks are the weakest of the bunch. We seriously advise upgrading in the near future as these can almost always be easily defeated by a good pair of bolt cutters or sharp pliers.
Chain Locks
These locks can be effective if paired with a closed shackle padlock. We also advise using a heavy duty chain as lighter chains can also be cut fairly easily.
U Locks / D Locks
These Bicycle locks in particular can be very good. They vary from brand to brand, but have the same solid metal core, just choose a thick one and you will be safe.