The "side channels" you speak of are actually the radius "slot" when cut...this retains overall strength at the beam portion of the rod and which also creates the "H" design. There is also a "straight slot" where this added detail machining is more on the precise end of things and also reduces overall weight of the entire rod mass. The straight slot que is strictly for assemblies trying to target a specific weight in mind for a targeted mass for a designated requirement for racing.