Update shoulder sprocket gear ratios.

Change-Id: Ie8a7442c54d6b77f41925cd590712435847d5f31
diff --git a/y2016/control_loops/python/shoulder.py b/y2016/control_loops/python/shoulder.py
index 9b70dbd..07a67f6 100755
--- a/y2016/control_loops/python/shoulder.py
+++ b/y2016/control_loops/python/shoulder.py
@@ -37,7 +37,7 @@
     # Torque constant
     self.Kt = self.stall_torque / self.stall_current
     # Gear ratio
-    self.G = (56.0 / 12.0) * (64.0 / 14.0) * (72.0 / 18.0) * (58.0 / 16.0)
+    self.G = (56.0 / 12.0) * (64.0 / 14.0) * (72.0 / 18.0) * (42.0 / 12.0)
 
     self.J = 3.0