I'd be a little concerned that you're abandoning the network you've built in SF. I guess it depends on the business you're starting, but when I co-founded my consulting company, all of our initial clients came from my existing network.
It all depends on how you interact with those people. If they are actually strong connections, which mine are, then you will not lose them by being in another city. They will also want to stay connected to you even though you are gone.