I use hillbilly shorts when mtb because I don’t bounce as well as I used to. [url:8kggwfsl]http://www.amazon.com/Hillbilly-protective-gear-27041-Impact/dp/B001CSYNZW/ref=sr_1_1?ie=UTF8&qid=1435080649&sr=8-1&keywords=hillbilly+shorts[/url:8kggwfsl] On the road I just wear running shorts and a very light running shirt. Your ass toughens up pretty quickly, especially if you are road biking a lot as well as mtb.