I have broken through some of the rubber tips and it is a little wierd moving up a pole and bringing your tip with you. The only problem I have is that I have used some older poles and those poles have washers in the rubber tips. One time I went through the rubber tip and the washer lodged itself sideways inside the pole about 2 inches up.
Maybe pole companies tried to use rubber tips to soften the blow when you plant???
ahh San Diego: women, sun , beaches, pole vault, what else do you need.