I'm still waiting to hear back from City Bicycle Works. They said they have a limited selection of road bikes for rent, but I'm waiting to hear on your size. Bicycles Plus has a great selection, but I know you don't want to travel 25 miles to get there! However, you could take light rail if you really want to come here to Folsom. They do have a wider selection of rentals, but it will mean wasting an hour or so each way in travel time (if you take light rail, and I know you said you don't have any other transportation).

I'll work on this more for you this weekend. You won't have to worry about being bored. I've just been swamped with work this week!