I will play Devil's Advocate a bit here:
There is a reason that the ride has a max participant limit. Sure, a lot of it has to do with aid stations (assuming there are any) and the supplies necessary to support the riders. So, if you are completely self-sufficient, you are not draining that resource.
However, I would be willing to be there are a host of other reasons for the cap. While all the roads may not be closed and every intersection may not have police, I would be willing to be there is some law enforcement support. In addition, in order to obtain permits from the various municipalities, I would be willing to be the organizers had to place limits on the numbers. Insurance for the event likely relies on numbers as well. Finally, those who actually paid for the ride have a reasonable expectation that they will only be surrounded by so many other riders.
By banditing the ride, you are disrupting those factors (and many more I am likely overlooking). Sure, 1 additional rider likely makes no difference, but, what about 10 or 25 or 50 ...
From an etiquette standpoint, IMO, totally uncool. From a legal standpoint, you are likely placing the event in jeopardy. (Again, not "you" as 1 additional rider, but, where does it stop?)
If there are no dogs in Heaven, then when I die I want to go where they went. - Will Rogers
Emery's Third Coast Triathlon | Tri Wisconsin Triathlon Team | Push Endurance | GLWR