I worked professionally as a motorcycle mechanic from mid 1970s through the early 1980s. Honda's service manuals were very good, but my favorites were the early

I worked professionally as a motorcycle mechanic from mid 1970s through the early 1980s. Honda's service manuals were very good, but my favorites were the early manuals from the late 1960s to mid 1970s, mostly for their Japanese to English translations. One of my favorite lines from an early CB750 manual was "Pleased to be applying the 26mm spanner to the castellated nut. Thank you." How can you not follow instructions when they are worded like that? I learned about train wheels decades ago, when I briefly ran through train history as an interest. What I found interesting at the time was how thoroughly this was understood right at the advent of the age of steam. Rail engineers understood this from the beginning. Another thing is that since the wheels ride an a narrow portion, going straight most of the time, wheel wear distorts the conical section, which leads to the wheels rubbing (instead of rolling) in corners, which accelerates the wear. So rail wheel wear is non-linear. Once the wear reaches a point wear it causes slipping/rubbing, it leads to positive feedback on the rate of wear. A failure mode that isn't obvious until you thing about it.