Recently, bicycling as a sport has attracted a great deal of attention. Previous research on bicycles suggests that pedaling at high frequency at a constant speed is most effective. However, it is hard for beginners to acquire such pedaling skills since expert cyclists develop the skills through long-term training. We propose a bicycle pedaling training system using auditory feedback. The system generates feedback sound every time a pedal crank turns a quarter rotation. Users can keep the pedaling speed constant by synchronizing pedaling with the feedback sound with background music whose tempo is constant. We conducted an experiment with eleven subjects for four weeks and confirmed that the variances of pedaling speed for the subjects trained with the proposed system decreased significantly compared with those of the conventional method.