The present invention is directed to a bicycle tool having multifarious functions. Specific problems that often occur in bicycles, such as chain-derailment, chain-shortening, and tire replacement, are all addressed by the tool of the present invention. It is common for a chain of a bicycle to become derailed, or removed, from its operative engagement with the gearing of a bicycle. It is also commonly required, when mounting a new chain on the gearing of a bicycle, to remove one or more links thereof to fit the specific type and size of bicycle. It is also common to have to replace a flat or worn tire by prying off the old tire and inserting a new one on the bicycle wheel-rim. The tool of the present invention may be used in all of the above-mentioned situations for assisting a person in achieving his desired task.