I was saddened to see that Sheldon Brown has passed away in the last couple of weeks. If you are a not a cyclist, you will possibly never have heard of him, but if you are, then you will know that his website was the "go-to" for all the technical tidbbits and technical advice on cycling that you could wish for. He also seems to have been a nice person along with it, and always had an interesting anecdote or story to go with his engineering expertise. RIP, Sheldon, and my thoughts to your family and friends.
