Originally Posted by FedError
Then basically Isner or Raonic. Throw in Gulbis as well, I missed him in my first post but he really goes for big second serves.
Of recently retired players, perhaps Taylor Dent and Joachim Johansson. In this article
Joachim talks about hitting second serves around the 200kmh (124 mph) mark.
Johansson was a guy who could fire a fault at 150 mph and then thunder in a second serve at 140. He actually did that in a Davis Cup match against Argentina (226 km/h against Schwank I believe). I wonder what went through his mind when he stepped up. Was it "I have an excellent first serve and I missed it, why not hit another one?" I have no idea. But I've never seen anyone consistently hit second serves as fast as Johansson. Scary is what it was. Would definitely call him one of the biggest hitters ever.