why is there a rule against changing bike during an event?

[David Lahey]

There has to be a reason why we have this rule, but I don't know what it is.
I'm interested in this because my time riding trials is very precious. If I ride a trial at the nearest big smoke (Brisbane), it means a driving trip of about 1300 km and taking at least one day's leave from work, so I can't afford to do it very often. If I can only ride one bike, and that bike gets a flat tyre, or the bars get broken, by the time I have fixed it, I need to rush to finish the trial, or DNF, which takes away a lot of the appeal.
I've done this bike swap thing many times in the past with the permission of the event organisers, and put both bikes through the machinery examination at sign-on. Some other times I have been allowed to ride both bikes as long as I ride non-competitive. I want to understand why there is a reluctance to allow people to swap bikes.
Here is what I understand of the current MA rules:
At Title events, use of a spare bike is not allowed
At other events, the use of a spare bike being allowed is at the discretion of the people running the event
Any parts on the bike being ridden in an event can be replaced at any time during any event

[Bully fanatic]

That is a good question David and it is one I would like to hear the answer for. Just going off what you wrote you could say that you have replaced every part on your motorcycle and that is why it looks different to what it did before. I know a few who have asked about changing bikes at a trial and have been told it is fine but you will have to ride non competitive. It is a rule that I think needs changing especially for older bikes as they can die easily and if they do you can`t ride legally. I only have one bike so it doesn`t affect me but I know a lot of people who would love to ride a different bike each day of a two day trial. Graham.

[Geoff Lewis]

Hi David, I imagine it is because the Trial competiton is meant to be a test of man and machine and the reliability of the machine is part of that, even if a small part these days. I could see the well heeled using a fresh bike each lap if allowed. I dont think that would really be in the spirit of the competition.
Regards Geoff.
PS. Anyone have a KT 250 seat to spare they want to sell ?

[PA]

In South Australia we include "Substitution of Motorcycle may be allowed, subject to the approval of the Clerk Of Course or Steward." in our Sup Regs.

[TooFastTim]

What Geoff said. Trials is, traditionally, a test of motorcyle reliability. I also agree that it is now mostly redundant.

I assume that if an arrangement can be made with the C-o-C there shouldn't be a problem. As a fellow competitor I wouldn't object.

[BOGWHEEL]

I think for a one day event - no change allowed is the rule and i'm fine with that.
But for Classic and Post Classic at two day events, why not be able to ride a different machine the second day? They are after all two different rounds of the series.
(Or at least let the guy coming last do it)