you gota remember that running an engine in a race enviroment is far more stressfull than what it would do as a road bike . This also goes for the bike as a whole . Otherwise for a MOT (sorry thats the yearly vehicle test you iom lot dont have to put up with ) you'd have to have all your bolts lockwired etc. otherwise you could say having a mot certificate is enough to race with and you dont need scrutineering ! A race bike is flat out all the time / full braking all the time you cant do that going to tesco's , well not all the time anyhow