If you are going to be in Kingsport, I'd advise taking your MTB or 'cross bike and go up to Abingdon Va. to check out the Virginia Creeper trail. It's a rail trail and not particulaly chalenging, but it's a beautiful and fun ride. 36miles long, it's the perfect family ride, easy, secenic, no cars, etc. There's plenty of info on-line about the trail, you can even rent a bike there if need be.