Circle Y & Tucker Saddle Sale or $ Discount + FREE SHIPPING WITH CODE TKCY. We're friend & family owned. Trade-Ins WELCOMED!
International orders receive additional discount at checkout!

Adjusting Saddle Fit with the T3 Matrix Shim Pad

Adjusting Saddle Fit with the T3 Matrix Shim Pad

Shim pads can help compensate for either a less-than-perfectly-fitting saddle or conformation issues with your horse’s back. The goal is to create a stable, comfortable, and balanced fit for your horse. Shims work best on saddles that are a little too wide, or in cases where the balance of the saddle doesn’t match the conformation of the horse. If the saddle is too narrow for the horse’s back, shimming will generally not solve this problem.



Your T3 Matrix Shim Pad comes equipped with:

  • 1 pair of Impact Protection inserts (Extreme Pro, Ortho, FlexForm)
  • 1 set of (12) ¼” felt shims (2/front, 2/middle, and 2/rear on each side)


The saddle pad opens with Velcro along the spine. This allows you to access the shims. Do not remove the Impact Protection inserts when shimming. Always fit your shim pad with the Impact Protection inserts. Adjusting the fit of your saddle is a process that can take some trial and error. Before adjusting the shims, we recommend that you:

  • Allow plenty of time for the evaluation process. Don’t rush.
  • Allow time to test ride in the shims, then dismount and untack to see how they are working and possibly adjust again for best fit.

To evaluate your saddle fit:

  1. Place the saddle on the horse’s back without a saddle pad.

  2. Check the saddle position: find the edge of the shoulder blade and trace around the bone with your fingertips, from the front of the shoulder, up and around toward the saddle. If you run into the saddle skirt, the shoulder should be able to rotate under it with little to no interference.

    Leave the saddle in this position. If your fingers run into the bars of the saddle (not the skirt) as you trace the shoulder, the saddle is too far forward and the saddle will interfere with the rotation of the shoulder blade. Move it back so the shoulder blade is clear of the bars of the saddle.

  3. With the saddle correctly positioned, you can now check the saddle fit: put your hand flat on the horse in front of the saddle where the bars of the saddle make contact with the horse’s back. Start to slide your hand along, under the saddle. If your hand has difficulty passing between the saddle and the horse, if your hand feels squeezed, this is a pressure point.

    You will remove a shim from this area. If your hand passes freely and perhaps you can even wiggle your fingers in empty space, the saddle is not making contact. You will add a shim to this area. If the pressure on your hand remains consistent from the front to the back of the saddle bars, the saddle has a good fit. Try the pad with no shims first.

  4. Add or remove one shim as your evaluation indicated, then place the pad under the saddle. Repeat step 3 to check the fit again, and add or remove as needed.

  5. Repeat this process on the other side of the horse.

  6. Tighten the cinch or girth and step back to examine the appearance of the saddle. If it appears level from front to back, go ahead and mount up. Evaluate how the saddle feels standing still, with your weight. Does the saddle feel balanced from side to side and front to back? Does it feel stable?

    If the saddle still looks it dives down at the front when it’s cinched, the tree is wider than the horse and you may need to add another shim to the front, each side. If the saddle is higher at the front than the back after shimming the middle and/or back, the tree may be too narrow for the horse. The saddle is probably not suitable for the horse.

  7. If all seems well, test ride for a few minutes of warm up. Dismount, untack and examine the back. If the sweat patterns are uniform or the back is largely dry, tack up again and continue riding.

Additional Notes

  • Continue to check on a regular basis throughout the riding season. As your horse becomes conditioned, muscles will change and consequently saddle fit will change.
  • Additional shim sets are sold separately.
  • If you find that you need more than 4 shims (total 1”) in one pocket, you should consider another saddle for your horse. Shims can only refine a saddle that does not fit perfectly. They are not intended to compensate for a saddle that is not suited to the horse, to begin with.


Do not use shims to compensate for or cover up medical conditions.