Originally Posted by ofofhy
Supposedly they also help in allowing condensation to evaporate out of the frame. They also allow you to spray frame saver into the chainstays, forks, and seat stays.
could be, i've never thought about condensation on the insides of the frame tubes. some frames, depending on the type of lugs, or welder, most of the tubes are interconnected, you can spray frame saver in through the BB shell, steer tube and seat post. the seat stays could be done from the brake bridge or seatpost if you have a weird lug make. the fork however, perhaps the brake hole?.. never seen a crown personally that would allow that though.