We get asked all the time about using pads to help a saddle fit better. First we’ll cover a tree that is too wide for a horse and then about the tree that is too narrow for a horse. To be clear when we talk about how wide a tree is we’re only talking about the front of the bars only. All trees flatten out as they go back. This is called the twist of the bars.
The starting angle of the bars is the most important area too get right. The pressure under the middle and rear of the tree loads and unloads with the movement of the horse. But because a saddle cinches up in the front, there is constant pressure under the front bar pads, right behind the horse’s shoulder blade.
Tree Too Wide
In the first picture you can see a tree that is too wide for the horse. The bottom edge of the bar pad is not contacting the horse. This loads and concentrates pressure on the top edge of the bar. So what happens when we add a pad?
The second picture shows this clearly. The pad will conform to the horse’s back but does nothing to add more contact area at the edge of the tree. There is still open space there. The weight of the rider is still loading up at the top edge of the bar.
So what about adding a thicker pad? The next picture shows that once again the pad conforms to the horse’s back but doesn’t add any more contact area. Most of the rider’s weight is still concentrated at the top edge of the bars. Not only that but the thicker the pad the more narrow the gullet becomes which can cause the saddle to bridge.
Tree Too Narrow
So what about the tree that is too narrow for a horse? The next picture shows no contact at the top edge of the bar with the bottom edge digging in to the horse's back.
A pad will not help in this situation either. Once again, the pad will conform to the horse's back and doesn't add any more contact at the top edge of the bar. The bottom edge of the tree is still digging into the horse's back.
The best way to check this out is to remove the skirts from the saddle and look at the bare tree on the horse's back. It's often hard to tell much about how the tree fits with the sheepskin and leather of the skirts hiding the tree from view.