Graeme....You know how they rode those bikes full hog for six days? Those bikes were the best you could get in their time and the riders knew no better. It was as easy for them as it is for a modern rider on a slick KTM. You do what you have to do with the tools you have at your disposal. I went as hard on my Sherpa S in 1969 as a young C grader does on his CR/YZ/KX/RM today and I bet I felt just as rooted after it was all over as my modern counterpart does today.