I wonder... The idea of an exhibition class for older bikes makes sense, but for the average viewer unaware of the finer distinctions of vintage dirtbike racing, wouldn't it be more interesting to see a variety of bikes? The use of the 'Evo' class perhaps makes it easier to include that variety, as under the MoMS Evolution is pretty much any dirtbike without watercooling/disk brakes. Which means we can see an old BSA/Triumph, a 1973 Elsinore, a 1979 Red Rocket or a 1984 CR500.
Surely, that range of old bikes is of more interest to the spectator who probably doesn't know or care whether a 1976 CR250 isn't Pre 75 legal or whether a single shock Husky isn't Pre 85 legal. From their point of view, it's about seeing old bikes out there and this formula ensures that they get to see a great representation of the older machinery.
I remain unconvinced that a field of real Evo bikes would have more impact than what the current arrangement permits. And given that I really doubt this display will convert a pile of spectators into serious vintage competitors, why worry about it's purity? I see it as an opportunity to intrigue, excite and impress the people who will enjoy seeing the old bikes out there.
Like I said before, short of heavily modified 500cc two strokes ridden by seriously fast young guns, the class is NOT going to impress anyone who couldn't care less about old bikes. It's not necessarily about how fast they go, it's about capturing the interest of people to whom the old bikes have some memorable attraction.
Trying to make a 1984 dirtbike go as fast as a modern is pointless, who the Hell cares? I'd rather watch a field of fast 450s than a bunch of old dinosaurs. But I *would* like to see a field of various vintage bikes from across the spectrum out there showing off the sight and sounds of yesteryear...