Originally Posted by kingfishr

In my 30 years of riding the only time someone passes and pulls in front of you is to let you draft although this is most common in club rides and organized rides. I have pulled in front of plenty of people without waving or introducing myself and let them draft me, always with the same effect, they are grateful and we usually start at conversation down the road or at the finish. You say you were doing 17-18 when pulled past you and slowed to 17, so my guess is he was trying to match your speed and probably underestimated. My reaction would have been draft for a few minutes and then to pull in front of him and set the pace I preferred 18, 19, 20... whatever and let him draft you. Waving while you are passing someone is not so easy, and looking back would have been dangerous. Maybe he should have said something in passing, but maybe he was a newbie as well and doesn't know the secret handshake yet.