I live in downtown Sacramento but I have not been on lately. From Old Sacramento you can get on the American River Bike Trail, which will take you all the way to Folsom. It's lovely this time of year -- we are having gorgeous weather, too.

ETA: Oh, March. Also lovely! Lovelier! Although it can be pretty windy. There is a place to rent bikes in Old Sac, I think, but they will be cruiser style, most likely. I will ask around about bike rentals and get back to you if you tell me what you are looking for.