While I'm right footed (kicking soccer balls, footballs, etc...) I don't believe either of my legs is any stronger than the other if only because of cycling. Pedal mashers may have different a experience, but if you've been trained to ride with a high cadence the mechanics of spinning will equal out any perceptable difference in leg strength over time. Consider working towards a targeted cadence of 90 - 100 and it will force you to develop a smoother, and fluid pedaling action that will allow you to ride longer with less fatigue.