"Welcoming" the horse’s back in motion requires that you MANAGE THE INTERFACE – which is the space between your horse’s body and the underside of the saddle. After incorporating a good saddle, this is the next most important factor for successful saddle fit when you want to give your horse the opportunity to enjoy the journey with you. With SmartSaddlePads.com saddle pads and tapered foam shims you are best equipped to custom fit the interface of your horse to adapt to individual age, top line shape and state of training.  SMARTFLX´S EXCLUSIVE, UNIQUELY SHAPED TREES ARE THE SUBSTRUCTURE AND MAJOR KEY TO SUCCESS OF ANY OF OUR SADDLES.  The very special SMARTFLX™ shape provides room needed for the horse’s back to come up in performance of any athletic maneuvers, especially ones requiring significant engagement or “collection”. Also sculpted into the SMARTFLX™ shape are the ergonomic considerations built in for the rider which enable feeling close to the horse´s body and it´s movement while securely balanced and unstressed in hip, knee and ankle joints. The “bars” and “groundseat” of the SMARTFLX™ western tree are a one-piece molded shape based on years of research and development incorporating thousands of horses worldwide. This molded piece is formed utilizing a particular, extraordinary elastomer compound material that is solid enough to support the rider and protect the horse's back yet flexible enough to allow the horse to move as nature intended and the human to feel connected in harmony. It is amazingly thin and keeps you close to your horse. Our wooden forks and cantles provide the base stability to hold the bars at the attitude and angle that our research proved was optimal. Our english saddles are constructed with the same principles regarding the spacious, welcoming shape we know is necessary for healthy, comfortable movement. English SMARTFLX™ trees are handcrafted by Master Saddlers in England utilizing digitally sculpted, laminated beechwood bars reinforced by steel head plate and thin diagonal steel bands that support appropriate diagonal flexibility. Because the SMARTFLX™ trees are sculpted to welcome the expanded “moving” horse body, there is room to accommodate an enormous variety of horse breeds and sizes.  SmartSaddlePads.com unique shimming concept provides a simple way to offer dynamic custom fit. The welcoming “hug” of our saddles’ undersides provides for a physically and mentally un-restricted equine athlete capable of enjoying full physical potential under saddle.I. STANDARD (STD) GULLET: The “STANDARD” tree is the narrowest gullet width we build, with subtle changes in attitude and angle along the bars that hug the moving horse without impeding in any way. Our open center channel does not impact the spine, of course and our broad, flatter-than-normal shape along the back invites optimum vertical and lateral flexion. Our "Standard" angles are approximately 10 degrees wider than "full quarter horse bars" and they are broader/flatter with less "rock". Observation of horses moving under saddle has consistently yielded evidence that bars narrower than ours, especially with "rock" shape get in the way of natural movement: they restrict the horses' shoulders and back, force high-headed/low back carriage and result in a myriad of other problems that are consequences of inefficient biomechanics. II. SUPERWIDE (SW) GULLET: The "SUPERWIDE" angles are approximately 10 degrees wider than the "STANDARD" and the bars are broader/flatter still. Broad backed horses (Warmbloods, wide Quarter Horses, Icelandics, wide-ribbed Arabians, Cobs, Drafts, Draft Crosses…and even wide-backed Mules) really travel beautifully/happily under our SW foundations. It should be noted that "wider" is not a simple matter of setting the bars further apart. There are many subtle changes of attitude/angles sculpted into our bar shape from front to back and left to right."