Where the tires are mounted on. Generally, there are one-piece rims and two-piece rims. Two-piece rims consist of two cup-like halfs, which are screwed together, while one-piece rims look like a spindle and consist, as the name suggests, of only one part. Today, one-piece rims are more popular, even though some people maintain that tires are easier to change on a two-piece rims. Sometimes, these are also referred to as one-piece or two-piece wheels.