MIKESPOLARA
Well-Known Member
two piece is the normal "billet" wheel and they are much better then a cast 1 piece wheel. However I will not spend $4k on wheelsYes, you're wrong - sorta, kinda, sometimes.
MOST "rims" are milled separately from the centers. The centers are milled then the rim is placed on a turntable and heated to expand it and the center is dropped in to the desired depth or offset. The assembly cools, is checked for runout and then the centers are welded in permanently on the back side. The fit is so tight it appears as a single unit unless you look at the back.
Some wheels are completely milled from a chunk. These would be mostly "one offs" where the shop wouldn't have access to a stock of rims.