There's a route that so many bikers have been waiting for in Atlanta of, taking amtrak west, getting off at the first stop (Anniston Alabama, 1 hour car drive away), and then riding all of the mountain bike trails at Coldwater Mountain. You could conceivably take the train back, or camp overnight in Piedmont Alabama and then ride the silver comet rail trail all the way back at some point.

Or just skip the mountain biking and take the train out and bike the silver comet all the way back home.

But! Amtrak won't let you take your bike off the train at Anniston. You have to go all the way to new orleans. It's really dumb and frustrating.