I bought a second hand hybrid bike and would like to adjust the stem of the handlebars such that I can ride it in a more upright position.
The following photo shows a side view of the stem with an arrow pointing in the direction I want to tilt it.
As you can see there is a hex bolt; a similar bolt is on the other side of the stem. I managed to loosen them on both sides (the bolt seen in the photo was very tough to turn), but could not get the stem to move.
What am I missing here?