I found the Bicycle Design Blog through a comment left yesterday. James designs home decor products but he also really likes bikes. "I like to ride them, work on them, look at them, think about them, and occasionally sketch them when I need a mental design break."
He has some slick looking bikes as well as commentary on bike design and I'm looking forward to seeing more. He writes, "I will keep posting design concepts and ideas and, hopefully, will eventually get some submissions from others." Check him out when you get a chance.