Not really! Rods, cranks, Pistons, etc. they are all forged & then machined. The forging process, compresses the metal molecules, making it denser and stronger. Then you can finish machine it. like a piston you take a forged piston slug, then you machine all the surfaces except for the hollow inside portion. The advantage is the piston is so much stronger than a cast one, you can machine it very thin and still be stronger than a cast piston.
On the wheels, some companies take a round disc forge it into a flatter round disc. Then machine a basket (BBS weave design, or long spokes) Its not as good as forging it into the desired final shape, because doing that your adding a grain to the metal also. But it's a lot better than just cast.