I would guess it depends on where you are and how tough the terrain. I’ve seen SS guys everywhere… they are crazy nuts. Where I live, in central IA, there are no "mountains" (barely even hills) and there are a lot of guys that ride SS all over the "mountain bike trails". Heck there are people who ride SS on things like Leadville. Crazy to me, but they do it and it’s super fun to watch them tackle stuff and do it with one gear.