Designability needed bearings and bushings that could deliver low-friction movement, alongside long-term durability and minimal maintenance. The products are often used outdoors, where reliability and safety are essential.
Because these components sit within the wheel system, which includes the brake, the suspension and the locking/release mechanism, they're regularly exposed to mud, dirt, road debris and water.
With conventional bearings, these levels of exposure would require regular maintenance or sealed bearings, which tend to be heavier, more expensive, and a costly compromise on a range of products built to be lightweight.