Yes indeed you need to somehow interpret it all rather than take it absolutely literally.If the replacing of worn out or broken parts was not allowed that would mean the end of the sport.Maintaining your bike is part of the sport wether its vintage or modern.The rules for period competitions are there to insure that the replacement of parts are correct for the period specified and that some competitors dont gain advantage over others buy modifying or installing more advanced components from a later period.Consumerables that everyone needs are not contendable.
Everybody needs them.
Nobody actually needs tech advanced components that have been appearing on vintage bikes more and more to ride or race and not everyone has the resources or even wants to install tech advanced components from the 90's and later on their vintage or Evo bikes.The Gcr's are there to keep the comp fair and accessable.I can't see how you can argue that allowing ofchanging a broken lever means that you can allow upgraded mechanical components on a machine as well.
As a foot note the hybrid class that has been discussed on this thread would be just that hybrid ,everybody would be aware that machines would have later conponents so no issue.The current Evo class is not a hybrid class and should never be.
cheers , no bad blood
Ah... now we're getting somewhere.
The next step is to work out "What is a consumable part?"... At the moment, the GCRs don't even try to consider them.
Stuff like tyres and chains are obvious, but what about exhaust pipes, rear shocks, handlebars, etc?
How do you write a rule that bans fat bars, but not old-school cross-brace-less alloy bars, or old-school 1" OD bars?
Similarly, how do you enforce a ban on PD valves without pulling down everyone's forks at every meeting?
In any historic form of motorsport, the equipment will be faster than it was when it was new - its unavoidable, due to the 25+++ years of increased knowledge (and developments to tyres, brake friction material, etc).
The trick it to work out what defines a bike (or car) as a historic, and to recognise that you can't totally stop the clock.
Personally, I don't think that a set of adjuster knobs on the rear shocks, or some bits inside the forks that you can't even see, makes a VMX bike any less vintage.