Bend is a gateway to the wilderness, so although there’s plenty of running in the city, there’s no need to stay close to town for the entirety of your visit. The local runners at FootZone recommend heading out on Phil’s Trail, which is the common name for a network of several trails starting about 4 miles west of Bend that span a total of about 40 miles between Skyliners Road and Route 372. While the trails are narrow in some areas, they are pretty non-technical and not at all rocky. For this reason, the smooth single track is also extremely popular with mountain bikers — so keep your head up as you go! The team at FootZone says if you go early in the morning (before 10am or so) there’s a better chance of getting the trails to yourself, bike free. The best parking is at the Trailhead just off Skyliners Road. As you head out Phil’s, you’ll gain most of your elevation on the way out. When you reach the intersection after about 4 miles, you can keep going, double back on Phil’s, or loop back on Kent’s trail.
There are plentiful additional options here. Best to consult a map. See the ‘mountain bike trail map’ link below.