Update shoulder sprocket gear ratios.

Change-Id: Ie8a7442c54d6b77f41925cd590712435847d5f31
diff --git a/y2016/constants.h b/y2016/constants.h
index 98d38c7..d9ae7c4 100644
--- a/y2016/constants.h
+++ b/y2016/constants.h
@@ -35,7 +35,7 @@
   static constexpr double kIntakeEncoderRatio =
       16.0 / 48.0 * 18.0 / 72.0 * 14.0 / 64.0;
   static constexpr double kShoulderEncoderRatio =
-      16.0 / 58.0 * 18.0 / 72.0 * 14.0 / 64.0;
+      12.0 / 42.0 * 18.0 / 72.0 * 14.0 / 64.0;
   static constexpr double kWristEncoderRatio =
       16.0 / 48.0 * 18.0 / 64.0 * 14.0 / 54.0;