The purpose of this study is to improve the stability and maneuverability of bicycles by controlling the trail effect according to the riding conditions of the bicycle. An experimental system is developed, and experiments are conducted to investigate the changes in bicycle behavior occurring due to the variation at the trail effect when the offset is varied. First, the bicycle behavior with different offsets is investigated by bicycle simulator. To verify the behavior depending on the size of the offset experimentally, we utilize the experimental bicycle for analysis in which the position of the offset can be changed in steps. As a result, a stable offset position at a speed of 10 km/h is confirmed by running experiments. A steer-by-wire mechanism bicycle, in which the handlebars and front wheel are mechanically separated and the front wheel can be electrically controlled without giving extra reaction force to the rider, is used to realize a preferable pseudotrail. From the experiments, with the steer-by-wire bicycle it is confirmed that the controlled bicycle reproduce the same behavior as the bicycle with the offset at a speed of 10 km/h. From the observation, we conclude the effectiveness of the steering-assisted bicycle in improving postural stability is confirmed.