You can buy a bike lock at your local bike store to ease yourself that your bike is secure. There are numerous models but the most common one is the Bike Master brand, which comes with three small keys and the joint of the lock itself is made of plastic. I’ve had numerous bike locks and the problem with this brand is that the plastic easily breaks, thus exposing the innards of the lock itself. I also find the chain itself too feeble and one quick snap of a giant cutter, and bye bye bike.
Thus, to protect my investment, I’ve come up with my DO-IT-YOURSELF bike lock. I bought a sturdy chain (you can even choose the chain pattern) in the local hardware store, plus I looked for the best combination padlock in the market. I wrapped the chain itself with cloth, so as not to scratch my frame, and to add aesthetics to the chain itself.
I don’t leave home without my bike lock now. If its just a short trip, I sling it over my helmet and shoulder and it is a bike fashion statement in itself. If there are mean boys who want to steal your bike, swing the bike lock around as if you’re Ghost Rider and give them a run for their money. Security, Statement, Swinger. That is my SSS Chainlock.