Q: How is a forged UP-04 different from a flow-formed wheel?

Forging presses a solid aluminum billet under high pressure so the grain follows the wheel shape, generally yielding more strength per pound than flow-forming, which stretches a cast barrel. That is why forged wheels like the UP-04 and its sibling the UP-02 tend to be the choice for owners who want both light weight and track durability. Flow-formed wheels can cost less, so the decision is strength and weight versus price.