to go from the 1.79 ratio to the 1.51, you need to change gears in both the upper and lower.
With the SX-M there two popular tooth counts, the 22/23 and the 21/26. Within the 22/23 Upper, you can choose from five different gear ratios. Those are 1.43, 1.51, 1.60, 1.66 and 1.85. As for the 21/26, we carry the 1.79, 1.97 and 2.18 ratios.welcome aboard