There are some good roads out in the country towards Jordan Lake and Harris Lake. There are a few dirt roads up that way, but I’ve only been on them once (so I wouldn’t be able to pin point where they are). You can always check gravelmap.com for dirt roads in the area. Just be aware, that it also marks bicycle only paths, so don’t get excited when you look at the American Tobacco Trail and think you’ve found a 20 mile dirt road gem in the Triangle! Same for the dirt roads at Umstead State Park.