There are many forms of racing. In recent years, road racing has brought, or played a large part in bringing, hydraulic rim brakes, electronic shifting, heart rate and power measurement. It has also brought carbon fiber wheels and other carbon fiber components, light yet strong enough for cobbled classics. I suspect it has played a large role in developing stronger carbon fiber frames that are light, stiff, and still compliant. Cyclocross racing has helped bring about road disc brakes, tubeless tires, single-chain ring drivetrains. Mountain bike racing was an initial impetus for suspension, disc brakes, tubeless, and many other innovations. There is also recumbent racing which has helped develop that type of bicycle as well as aerodynamic aids.