Periodic flow inversions have been shown as an effective means to eliminate both density (D system) and size (S system) segregation. The frequency of these inversions, however, is the key to applying this technique and is directly related to the inverse of the characteristic time of segregation. In this work, we study size segregation (S system) and adapt a size segregation model to compliment existing work on density segregation and, ultimately, aid in determining the critical forcing frequency for S systems. We determine the impact on mixing and segregation of both the binary size ratio and the length of each leg of a "zigzag chute". Mixing is observed when L < U tS, where L, U, and t(S) denote the length of each leg of the zigzag chute, the average streamwise flow velocity of the particle, and the characteristic time of segregation, respectively.