I completely agree with revortay1. You want to train all of your muscle groups evenly. Otherwise, you risk raising your exposure to injury. Think about it... you don't just use one side of your body in your everyday activities. Both sides balance each other out.
With that said, you should feel the strongest contraction in your right abs and obliques when you bring your left elbow to your right knee. But again: I would not advise targeting a single side of your body. If you're not happy with your results from Bicycles, mix things up with the Captain's Chair, the Plank, etc.