No matter what your goals are as a weight lifter, the bike is an exercise that needs to be included in your free workout routines.  Why?  The bike provides many benefits to how your muscle strenthens.  Of course, the bike is a great exercise for the legs.  It helps you strengthen your legs through exercises like the squat because the bike lengthens the muscle.  However, there are more benefits of biking.  For instance, because biking is a aerobic exercise, it helps strengthen the core of your body.  With a stronger core, you can strengthen your whole body easier.  Also, the bike is a great warmup exercise for leg exercises like the squat or the leg press.