Guys,
Racers, change their oil after every race, the engine's construction is often totally different to touring/Sports road models often also using different alloys, tolerances e.t.c.
The race bikes engine has only to hold together for the race that it is in and can be rebuilt afterwards, that's why the IOM and Bol d'Or Paris Dakar type races are so lethal to engines and machines, as a whole the product got to be bullet proof to win, also the stresses vibrations revs and narrow power-bands demand the utmost from the metals and oil lubrication system, this is not always so on the road, conditions and stresses vary and the oils used have to reflect this.
I not saying racing doesn't " improve the breed", its just that the nature of the beast differs so widely.
Cheers
JBW
