Re-inventing the ride

Advanced engineering and lightweight materials have helped give the saddle its first major redesign for 200 years. Berenice Baker reports

Its design has remained unchanged for over 200 years, accounted for generations of bow-legged cowboys, and the early retirement of many a racehorse. It is, of course, the riding saddle.

But according to Surrey-based equestrian specialist Quantum, clichés such as ‘saddle-sore’ could soon be a thing of the past thanks to a completely re-engineered saddle that exploits technical know-how from the auto industry and some of the most advanced materials available.

The story began when extreme sports enthusiast and owner of Quay Equestrian, the late Andrew Stockford, questioned whether the strong, lightweight materials used in other sports such as climbing, skiing and sky-diving could be applied to horse-riding. In a gesture cleverly calculated to appeal to design engineers he parcelled up a traditional saddle and sent it to design consultancy SeymourPowell with a note saying, ‘We should be able to do better than this.’ Ten years, and £1m investment later and the Quantum Saddle — a lightweight, precision-engineered saddle that promises improved comfort and safety for both horse and rider — is finally on sale.

Much of the detailed design was carried out by the UK arm of engineering group ARRK R&D. The company’s business development manager, Mike Gilmore, explained that the designers used the same approach with which they tackle their more familiar business of developing car components and consumer products. ‘The design is driven by the technology, rather than working to fit a particular shape,’ he said. ‘We input target load cases that the saddle needed to achieve, and set realistic weights to achieve to optimise each part using intelligent computer-aided engineering (CAE).’

Richard Wright, ARRK’s engineer for the project, said that beyond key objectives of improving the pressure distribution on the horse’s backs and reducing the overall weight, the team had to start from scratch. They began by looking at the problems with current saddles.

A useful starting point was an existing study carried out by researchers at King’s College London into working horses that have a hefty weight on their backs for long durations, such as those of the Household Cavalry. When not on duty, training exercises involve jumping and dressage manoeuvres, which place an additional demand on the horse. Many of them go lame and are retired from working life relatively young. Similarly, many of the guards suffer with back problems. The study found that these concerns can mainly be attributed to the saddle and its load distribution.

The Quantum team built on this knowledge with its own tests. A horse and rider were instrumented with an accelerometer on the rear underside of the saddle, and at core stages along the stirrup strap. A data logger was fitted to a rucksack so that it could be carried by the rider to capture the duty cycle. In the same way that a voice track is recorded to match events in car testing against readings, the team made videos of the horse and rider in action to synchronise load data with, for example, impact following a jump.

Quantum company director Matthew Stockford, Andrew’s brother, explained: ‘Traditional saddles tend to create pressure hotspots, most notably round the stirrup bars at the front of the saddle near the horse’s shoulders. That can cause rubbing, pain, injury and muscle wasting round the withers. At the performance end, you’re looking for your horse to have maximum muscle build and maximum fitness. If you’ve got any restrictions round that area, it’s going to impact on the performance of the horse.’

To counteract the pressure points, the designers developed a carbon-fibre fin with automotive carbon composite supplier Reverie. As well as being light, carbon fibre is very rigid, so wherever a load is applied it distributes it down the full length, in this case across the horse’s back.

A traditional saddle is underpinned by a structure called a saddle tree, which consists of a U-shape that goes over the horse’s wither (the ridge between the shoulder blades) and a fitting going out towards the back, which is where the seat is fitted. The stirrup bars are right at the front of the tree, so when the rider stands up and puts his full weight on the stirrups, it creates a pressure point.

The stiffness of the carbon fibre enabled the position of the stirrup bar to be moved backwards and cantilevered into the right position to shift any restriction away from the horse’s shoulders.

Carbon fibre can also be made flexible, and this was exploited in the seat pan, which is cantilevered off the main saddle, isolating the rider from the horse so the seat can bounce up and down on top of it without putting too much load on the animal.

That seat pan consists of two layers of thin carbon-fibre skin separated by a foam core so it is lightweight but quite stiff. It is attached at the front part of the saddle with a rubber buffer under the rider’s bottom, so in extreme cases when it comes into contact with the fin, there is a cushioning effect. By allowing the seat to move relatively freely to dissipate energy, the horse does not experience the full load.

Two types of foam supplied by Stirling Moulded Composites were used: a closed-cell foam of two different densities with a membrane to allow a free passage for air between them, and an open-cell foam, which is much softer.

The team made a 3D scan of a horse’s back which they used to construct a glass-fibre model as a representative test rig for cyclic testing of the components. There were two main streams of testing: applying service loads and verifying durability. The testers attached webbing straps to the stirrups and repeatedly and continuously applied forces of a level that they had measured in earlier testing. After this they increased the load until unit failure.

The aluminium parts for the bridge piece and stirrup bars, made by climbing gear manufacturer DMM, then had to be moulded into the carbon-fibre saddle, and the team had to develop transition pieces to make sure that the load was transferred effectively and didn’t just rip out of the carbon fibre.

At this stage, the team began constructing prototype saddles. In early versions, the thinking was if the stirrup bar was cantilevered from the back of the saddle, it would move back from the horse’s shoulders. However, prototypes demonstrated the cantilever was too much as it made the saddle pivot forwards and the rider did not have a stable base, so the cantilever was shortened.

An appliance pressure test mat — a thin electrical mat with pressure sensors in — was fitted between the horse’s back and the saddle. Data from it gives a pressure map with blacks and greens where there is low pressure, and reds and pinks at pressure hot spots. In terms of the horse’s comfort, the holy grail is even pressure distribution away from the shoulders, and this was demonstrated through the pressure mat and confirmed through video gait analysis.

The first available model is a jump saddle but other models will follow. ‘The clever bit is that the chassis underneath stays the same,’ said ARRK’s Gilmore. ‘Unlike a conventional saddle where you’d have a different tree, and everything else would be different, on this you just get a new top to fit onto the same chassis.’

With traditional saddles available second hand for a few hundred pounds, the Quantum saddle’s hefty price tag — it costs £2,750 — makes it a serious piece of kit. But according to the manufacturer, it’s going down a storm in equestrian circles, with leading British showjumpers Cressy Clague Reading, Geoff Luckett and Gemma Paternoster all embracing the technology in recent months.