The tree is the internal framework of a saddle — the rigid or semi-rigid skeleton around which all the leather, panels, and fittings are built. It is the single most important structural element of any saddle, and its fit to the individual horse directly determines whether the saddle distributes the rider’s weight correctly across the horse’s back or creates localised pressure that causes pain, resistance, and ultimately physical damage.
What a Saddle Tree Is Made Of
Traditional trees were made from beech wood, laminated and shaped to specific measurements. Many high-quality traditional saddles — particularly from British makers — still use a wooden tree reinforced with steel gullet plates and spring steel strips running down each bar. The result is a tree that is durable, offers some flex under load, and can be reflocked (re-stuffed) and adjusted by a saddle fitter over many years.
Modern synthetic trees use glass-fibre, carbon-fibre composites, or injection-moulded polymers. These are lighter, often cheaper to produce, and can be engineered with very precise flex patterns. Some synthetic trees are designed to flex laterally — particularly in cross-country saddles, where the rider’s weight shifts dynamically through combinations and water complexes. However, not all synthetic trees are equal: a low-quality polymer tree can distort under load, losing its shape and becoming dangerously uneven over time.
Key Components of the Tree
The tree consists of several distinct structural zones:
The head (or pommel arch). The front of the tree, bridging over the horse’s withers. The angle and width of the head determines whether the saddle clears the withers correctly. A head that is too narrow pinches; one that is too wide drops onto the withers directly. Either creates pain at the most prominent bony landmark on the horse’s topline.
The gullet plate. The steel reinforcement at the head, which determines the gullet width — the channel running the length of the saddle’s centre. This channel must remain clear of the horse’s spine at all times; a saddle that bridges or drops onto the spine causes concentrated pressure on the vertebral processes.
The bars. The two arms of the tree that run along either side of the horse’s back, distributing the rider’s weight over the largest possible area of muscle. Bar angle — measured in degrees — must match the horse’s back angle. Bars angled too steeply pinch; too flat, and they rock on the horse’s sides.
The cantle. The rear upward arch of the tree, framing the back of the seat. The cantle height affects the rider’s position and security, and varies considerably between disciplines — a Western saddle has a very pronounced cantle to support the rider during working manoeuvres, while a flat-race saddle has virtually none.
Tree Width and Horse Conformation
Tree width is the measurement that saddle fitters focus on most, usually expressed as Narrow (N), Medium Narrow (MN), Medium (M), Medium Wide (MW), Wide (W), or Extra Wide (XW). Thoroughbreds and finer-built horses typically take a medium-narrow to medium tree; heavier-set Warmblood types or cobs often require wide or extra-wide. As a horse builds muscle through correct training, its back shape changes — a saddle that fitted perfectly as a four-year-old may need tree adjustment or replacement by age seven.
A qualified saddle fitter, ideally a Fellow or Member of the Society of Master Saddlers (SMS), assesses tree fit by evaluating the saddle on the horse in motion and at rest, checking for rocking, tilting, pinching, or bridging — all signs that the tree is not the right shape for that horse’s back.
Frequently Asked Questions
Can a saddle tree be adjusted?
Traditional wooden trees with adjustable gullet plates can be re-set by a qualified saddle fitter — it involves opening the saddle, modifying the gullet plate angle, and reflocking the panels. Some synthetic trees use interchangeable gullet plates that can be swapped without opening the saddle. However, not all trees are adjustable, and attempting tree adjustment without proper training can damage the saddle irreparably. Always consult a qualified saddle fitter.
What happens if the saddle tree is broken?
A broken tree creates sharp, uneven pressure points that can cause serious injury to the horse’s back. A tree can crack from a fall, being dropped, or being sat on while on the floor. Test for a broken tree by holding the cantle and pommel and gently twisting — there should be a small amount of flex but no creak or grinding sensation. If in doubt, have it assessed professionally before riding. Riding on a broken tree is not worth the risk to the horse or the rider’s position.
How often should saddle fit be checked?
The BHS and the Society of Master Saddlers both recommend having saddle fit assessed at least once a year, and whenever the horse’s body condition changes significantly — after a period of illness, a change in workload, or a change in rider. Young horses in work should be checked more frequently as their musculature develops rapidly.