My advice when evaluating advice on which weapon to use in self defense is to begin by ignoring anyone who talks about this weapon or that weapon without relaying the time he or she used it. That's just stroking.

Living in Portland you're lucky to have several places to study Mixed Martial Arts, also known as Ultimate Fighting. Although competitive in orientation it's also the best place to learn the all-around nature of fighting. It is one of few martial arts that follows a scientific method, by having controlled experiments (fights with rules) that determine what might happen under uncontrolled conditions (an attack in the real world).

If you don't want to get hit you can study grappling, or Brazilian Jiu-jitsu, and obtain possibly a more effective education in self-defense, by learning instincts that will resolve a conflict quicker than hitting will. I myself took a year of Judo and count myself substantially better off for it. I have defended myself with it many times...one memorable time I was 'tai otoshi'd by a wire on the floor and executed a graceful roll!

Human conflicts are overrated; having studied the dynamics of them I know when to be afraid. Most of the time I'm not.

As for carrying a weapon...don't. The only weapon likely to prove useful if you don't know hand-to-hand combat is a gun, and that gun is also less likely to prove useful than people want it to given the prevalence of violence emerging from within close quarters. Anything else must be deployed from a basic platform of hand-to-hand competence, or anyone with a gift for brawling or some training is going to take you off balance, knock you over and put the hurt on you weapon or not.

You're a younger guy with lots of youthful flexibility and I hope a good attitude to go with it. Do a semester of ultimate fighting and you'll see the entire picture differently, and you'll get an explosive sort of strength that cycling just can't give you, the kind people use to toss shotputs or clean-and-jerk weights.