The Tasmanian, who confirmed he is leaving Team Sky at the end of the year live on SBS after the the Stage 9 team time trial, laid out his reasoning in more detail during the Tour's first rest day.
"At 30 years of age, I feel I am at the optimal period of my career and I really want to make a fist of leading a team regularly," he told Fairfax Media.
"So I need to make the leap of faith and find out for myself if I am capable of it, which I believe I am. But the rider I am in the future will always be a by-product of four years of development at Team Sky."
Porte maintained that he would give his all in support of team-mate Chris Froome's tilt for a second Tour victory, which is so far going to plan. Froome currently holds the maillot jaune, albeit by a slim margin from BMC Racing's Tejay Van Garderen.
"I'm here with Team Sky; I'm wearing the Sky kit. I love this team," Porte told assembled media during the rest day.
"Froomey is one of my closest friends and so are the rest of the guys. I know what my job is here and I'm excited now to get into the mountains. If you're talking about (Nairo) Quintana and all these other guys, (Vincenzo) Nibali, I can't wait to chase them.
"That's my job and, if they attack, I'm going to chase them for my mate Froomey. I'm looking forward to it."