In this study, we have been developing an active training wheel for the acquisition of the bicycle riding. This wheel is designed to support to recovery the slant angle not to fall down as if a parent correct the slant angle from backside when it is necessary in the practice. The rolling angle of these wheels are movable, so usually the wheels are set to the high position not to land and disturb the practice, and the wheel moves to land if the falling down risk is anticipated. After the development of our first model, we inserted an air spring between the joint and the wheel. This spring enables soft landing and quick recovery to the neutral position. The repulsion force, however, must be controlled not to roll over. In this study, we first modify the training wheel mechanism. After this renewal, the training wheel moved very smoothly. Next, we investigated a control algorism to control the repulsion force. After the basic response experiments, we decided to control the wheel by the angular velocity of the 5 degree when the bike is going to fall down. We also planned and made a robot riding simulator because this type of active training wheel has a possibility of the rolling over accidents. We have to examine the safety of this training system by using robot simulator before using real riding practice.