Have you ever cycled over the Fleak (the road between Wensleydale and Swaledale for people who find the Buttertubs too easy)? I did that when I was 17, on my roadster with Sturmey-Archer 3-speed hub (see one of my earlier posts). I didn't know that I was cycling over the Fleak; I only had a 4-inches-to-the-mile road map with no indication of topography; but I did know that it was very hard work.