There is a huge area on and around the Maiella for mountain biking, but there are also trails nearer to the house such as these ones near Guardiagrele which is less than half an hour away. Bikelife is also a useful site for routes and other bike related information in Abruzzo. This website also shows the trails up on the Gran Sasso which is further away. Just take care to ensure that the trail you are on is a valid biking trail. Also Bikehelp provide bike rental but I am sure there are others.