This is based on an article that I wrote for Spokenotes, my bike club’s newsletter, but reworded and with more pictures. Pictures and diagrams are actually a very powerful learning tool for engineering; as an example, I learned how a 14 speed gear hub works primarily from a book that is written in German. I can’t read or speak German at all, but I could understand the pictures and diagrams in the book, and even spotted a mistake in one of them. But I digress. Hopefully from this article you will not only learn how to pull a dynamo hub apart, but you will also get a good idea of how they actually work. Having a background in physics would probably be useful for the latter, but hey, it’s not like it’s general relativity; I learned about electrical generators in high school. Continue reading “Dynamo hub overhaul”