Gyro Power

Google has brought forth a self-driving bicycle. Using a remote control a person can send it coordinates and it will fetch said person like a taxi. I found no information on the inter workings, but it was impossible to knock over. I’m surprised a gyroscope too small to be easily recognizable could exert such an opposing force. What is the rule? reaction lags the applied force by 90 degrees, or does it lead the applied force? (it’s been nearly 50 years since I’ve worked on aircraft systems using stabilization gyroscopes).