Since I haven't heard about other rides, thought I would throw this one out as a possibility. I'm open to other routes as well (Davis for example?).
I've worked out a combination of a couple of rides. The loop can either start in Folsom, or near me on the ARBT at Hagan Park. From the start, the Loomis loop followed by a loop around Folsom. If we start in Folsom, I expect a little short of 50 miles. If we start here near where I am, it'll be more like 75. Either way, I'm likely to cycle to the start. There aren't any big climbs on this route, though the accumulation of hills adds up to over 3000 feet of climbing.
I'm thinking 9 am start. There's a grocery store on the route with a pretty good deli for lunch. Karen's Bakery is not open on Sunday's .