There are actually two types of links alternating in the bush roller chain. The 1st type is inner links, having two inner plates held with each other by two sleeves or bushings upon which rotate two rollers. Inner links alternate with the second type, the external links, comprising two outer plates held with each other by pins moving through the bushings of the inner links. The “bushingless” roller chain is comparable in operation though not in building; instead of separate bushings or sleeves keeping the inner plates together, the plate has a tube stamped into it protruding from the hole which serves the same purpose. This has the advantage of removing one part of assembly of the chain.

The roller chain design reduces friction compared to simpler designs, resulting in higher efficiency and less wear. The initial power Drive Chain transmission chain types lacked rollers and bushings, with both inner and outer plates held by pins which directly contacted the sprocket tooth; nevertheless this configuration exhibited extremely rapid wear of both sprocket tooth, and the plates where they pivoted on the pins. This problem was partially solved by the development of bushed chains, with the pins keeping the outer plates moving through bushings or sleeves linking the inner plates. This distributed the wear over a greater area; however the teeth of the sprockets still wore more rapidly than is desirable, from the sliding friction against the bushings. The addition of rollers surrounding the bushing sleeves of the chain and provided rolling contact with one’s teeth of the sprockets resulting in excellent resistance to wear of both sprockets and chain as well. There is even very low friction, as long as the chain is sufficiently lubricated. Constant, clean, lubrication of roller chains is of principal importance for efficient procedure and also correct tensioning.