I don't disagree with any of that Ross, but to provide a counter-point (I'm going to labour on the Yamaha hub thing, but I'm sure there similar issues that relate to everyone's bike/s - so don't go thinking that I'm obsessing over this particular issue - its just a convenient example):
1. Lots of stuff is legally non-era. Personally, I find a 1K7 front hub to be a lot less visually offensive than a set of modern 'fat bars' - and conventional 7/8" bars are a lot easier to find (and fit) than a 322 hub. Unlike the bars, a 1K7 hub offers no tangible performance gains.
2. Lots of stuff has been accepted for a long time (rightly or wrongly). To suddenly crack down on hubs that are missing nine small, ineffective webs, is to risk upsetting a bunch of riders who have bikes that have been considered legal for many years, including previous VMX Nats.
3. As a rider, I don't give a rat's arse if I'm beaten by someone with the wrong front hub, or a pipe that runs the wrong way, or whatever. Given the infrequency of protests over these issues (and the fact that the protester is generally viewed as a twit when they have protested), I figure that my view is shared by the majority of VMXers.
Maybe I'd have a different view if I was beaten to the silverware by someone who has an illegal set of forks or barrel or too much suspension travel (ie: Something that clearly makes a difference) but until then...
4. Several of my pre-77 bikes have 1K7 hubs. Given how difficult/relatively expensive finding and fitting 322 hubs is, at least a couple of those bikes wouldn't have even been built if the 1K7s weren't acceptable.
Those couple of bikes weren't built to be Nationals bikes (ie: They're low cost shitters), and they're only designed to have some fun at club events - so you could argue that it makes no difference - but are we encoruaging participation in the sport, particularly when the bikes are arguably within the 'spirit of the era'.
Or are we discouraging participation? If so, why is that a good thing?
Even if I look at my more serious (ha!) race bikes, knowing that I'm going to have to chase hubs, respoke wheels, etc, greatly dampens my enthusiasm for the event - making me less likely to turn up...
Good for the sport?
5. Sometimes, riding up an era isn't really an option - if I make it to this year's nats, I'll take a pre-75 125 and a pre-78 one - so bumping the pre-75 bike into pre-78 will mean that I go lose a ride.
Australian car rallying is being killing by its administrators at the moment, through a peculiar mix of utter neglect and pedantic meddling. All of the troops are up in arms over this, and a lot has been said about it, and its invariably been ignored...
The one simple message that seems to have a hope of getting through, is asking them to finish every statement with "....and I'm doing this for the good of the sport".
Now, I'm not claiming that VMX is suffering from the same afflication - this thread shows that our commissioners are actively trying to do the right thing, and I reckon that's great.
But the simple principle of stating "This is good for the sport" is an excellent way of keeping the focus on the outcomes rather than the process.