A track support rail for slidably supporting a track assembly of a machine includes a body having a first body end, a second body end, a crown portion, and an upper support surface. The body extends along a longitudinal axis between the first and second body ends. The crown portion is disposed between the first and second body ends along the longitudinal axis. The upper support surface extends along the longitudinal axis between the first and second body ends. The upper support surface includes first and second curved segments. The first curved segment has a first curved shape and extends from the first body end toward the crown portion of the body. The second curved segment has a second curved shape and extends from the second body end toward the crown portion of the body. The first curved shape is different from the second curved shape.