I was going over some of my bikes today and noticed all of the Bottom Bracket cable guides were a little different. Even within the same brand there were differences. It got me thinking about how little I know about this frame component. So help me out with info on cable guides. Were they made by the frame/dropout/lug companies or the builders themselves? Was this a detail of the bike that the builder would try to make stand out? Any info would be interesting to discuss.