Can a saddle be too long for a horse?

Saddle length on a horse demonstrating it being longer than it should be

written by Kay Hastilow Master Saddler, Master Saddle Fitter.

Have you been wondering whether a saddle can be too long for a horse?

In this article, Master Saddler Kay Hastilow offers a lending hand to explain the safe length of a saddle over the horse’s back and what can be done to help the rider get more seat without impacting the horse.

Can the saddle length cause a problem?

Without a doubt, there are dangers of using a saddle that is too long for your horse’s back, however, there are also ways in which you, the rider can obtain a little more length and comfort without impacting the horse’s back.


Let’s use a common scenario to start us off…

The rider has been told by an expert in the ‘horse’s back’ department, that their saddle is too long for the horse. The specialist then goes on to say this is causing the horse harm and that they must buy a 16 ½” to keep within the T18 boundary over the horse’s back.

The rider is around 5’6” and weighs 11 stone. Not big by anyone’s standard and probably considered to be a healthy height-to-weight ratio, yet for them to ride in most 16 ½” saddles would be extremely uncomfortable as it would be too small. Perhaps you think that they should just put up with this if it’s for the good of their horse, right?

Wrong …

If the rider’s weight is concentrated over too small of an area than needed, it will add considerable pressure on the horse’s back which can too cause pain and damage. In addition, if the rider is uncomfortable in the saddle, they will be constantly moving as they attempt to find somewhere to comfortably sit. Excessive movement by the rider could cause the horse to be unbalanced, as well as withstanding sores and bruised ribs.

Natural Balance

A horse is constantly trying to balance both themselves and the rider. Anyone that has ever backed a young horse will know how they move initially like a dyslexic spider as they try to balance both themselves and this strange thing on their back. As the horse progresses in its career, this situation gets easier, but this doesn’t mean that they aren’t still re-balancing to accommodate the rider. Every time a rider moves about trying to find a sweet spot, in a saddle that is too small for example, they are unbalancing the horse. He then must correct, repeatedly. This is unbelievably tiring and completely counterproductive.

Looking to T18 for the answer

So, T18. Why is it considered to be the furthest back that a saddle can go?

T18 is the point at which the horse’s last rib comes off the thoracic vertebra and is therefore considered to be the last strong area of the back with regard to supporting weight. Beyond this are usually 6 lumbar vertebrae which are not supported by the rib cage and therefore unsupported beyond their length down the horse’s sides.

T18 is the point at which the horse’s last rib comes off the thoracic vertebra and is therefore considered to be the last strong area of the back with regard to supporting weight.

Having a saddle that can fit a bigger rider without causing pressure past the T18 region can help the horse and rider be more comfortable and get to the job at hand, but how can this be achieved?

Increasing the size of the saddle without adding length

Let’s think initially about the saddle itself. Although the shape of the tree should conform to the shape of the horse’s back it is possible, during manufacturing, to make the seat much flatter if necessary by rasping down the cantle and webbing up tighter. This will give the rider more area to sit comfortably. Saddles with broader seated trees are also available which, provided the horse’s back can support that width, will give the rider yet more room. Likewise, flaps can be cut longer and further forward to accommodate the rider’s legs. Especially useful for our taller riders who will find themselves sitting on the very back of the saddle whilst trying to find somewhere for their legs to go.

Saddle balance

The balance of the saddle is also always very important. A saddle that is too small for the rider can tip the weight backwards which can add more pressure to the lumbar region. Please remember that a horse dynamic (in this case ridden) will be a totally different shape than static so that a saddle that appears to be in balance static can change totally once the horse works. They don’t always lift either. Some lift, some drop and some stay the same. Because of this no saddle fit where the horse is not ridden in that particular saddle is of any value whatsoever. It can all change in a moment with movement.  

Weight bearing area of the saddle

So far so good, but a very important factor has not yet been considered. The first is that the length of the saddle overall is not all completely weight-bearing as, beyond the parameters of the tree, there is little real downward pressure. The panel will fold away from the back without the tree to keep the downward force. In many saddles, the area beyond the tree parameters at the back can extend for another 5cm, yet this area really is causing no trouble to the horse whatsoever.

The tree of a saddle sat on a horses back.
The tree of the saddle which acts as the weight bearing area
Have you been wondering whether saddle length is a problem for your horse?
A visual of where the tree sits inside the saddle and how this then relays to the horse’s back.

The impact of movement on the length

Another factor to consider is that these horse experts rarely if ever see the horse ridden, and yet we know that just a slight change in outline when dynamic (moving), as opposed to static, can lead to the area available to take a saddle increasing by up to 5 cm! 2 whole inches! Using laser measuring equipment we marked a horse at the point of the shoulder and just down from the vertebrae at T 18 and measured when standing and again when just encouraged into a more ridden outline. I think all were surprised at just how much different these measurements were – a full 5 cm initially and, with further measuring in other situations this was repeated and repeatable, we even gained another 3.5 cm with a 23-year-old horse with a considerably dipped back. We really didn’t expect that.

We know that just a slight change in outline when dynamic (moving), as opposed to static, can lead to the area available to take a saddle increasing by up to 5 cm! 2 whole inches!

So, what is happening for this to happen? Certainly, the back itself isn’t lengthening – the thoracic vertebrae are tightly joined, and I doubt that you would get more than 1 cm in any circumstance, but the dorsal spinous processes? That’s a different matter and one can believe that these open as the horse ‘lifts his back’ as he works.

Now, as is self-evident I am no scientist, but I am very observant. I hope that you are as well and, having read this think ‘well, I could try that. Just use a tape measure with the horse relaxed and again with it more in an outline’.  You can also mark T18 with some tape, put your saddle on (neatly cut numnah so that you can see, not a huge saddle square) and you will probably be covering the tape. Go ride the horse and have someone film you. Almost certainly you will clearly see the tape.

Now that we know that the static horse is shorter in the back than the dynamic horse we can allow for a longer saddle, especially as we are aware that beyond the actual tree, there is unlikely to be much pressure, we can fit a saddle that is suitable for both horse and rider. In fact, in conversation with other saddle fitters, it seems that many of us believe it is better for the horse to have a saddle that, even considering the above information, is still a touch too long, but in which the rider is comfortable.

Fit with thought, fit with care but fit with knowledge.

About Kay

Kay trained as a bench saddler with Bliss and Co, London in the late 1960s. Having set up her own manufacturing and retailing business in the 1970s she became increasingly interested in the effect that the fit of the saddle had on her own showjumping horses and, from the late 70s onwards concentrated her efforts on saddle fitting.

In 1995 the Society of Master Saddlers set up their course and qualification for saddle fitting and Kay taught on this course from then until and including 2021, for most of this time as lead lecturer.

Now semi-retired she still lectures and teaches in various countries and when not doing this spends most of her time at her home in Scotland with her horses and playing golf.

For more information visit Master Saddlers or contact The Society of Master Saddlers on 01449 711642.

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