they are Nathan, the rules were'nt written to delete bikes from the class, they were written to define a specific era. they are saying, to keep these few bikes in this era, which is what we want, lets ( right or wrong) bring them in line with the majority to define the class, and that is reduce your suspension to 9".
it's not that hard, you just have to race to the rules
and I have a YZ400D with a fox airshock fitted that meets the guidelines as I want to race pre78 and not evo on this bike
worms