The Complete Handbook of Reins

Chapter 1: Understanding Reins

Reins are a direct mechanical link between the rider's hands and the horse's mouth, and they are one of the most misunderstood pieces of equipment in horsemanship. Most riders use them without thinking much about what they are, how they work, or why different reins behave differently. Professionals—instructors, trainers, farriers, and facility managers—often make decisions about reins based on tradition, habit, or marketing claims rather than a clear understanding of how they function. This chapter establishes the foundation: what reins actually are, the mechanical work they do, why they matter, and why the specifications and materials you choose have real consequences for both communication and control.

The Basic Problem Reins Solve

A rider sits on a horse's back, roughly six feet above the ground, with no structural connection to the animal except through the saddle and seat. The rider cannot physically hold or push the horse's head. Direct physical control of a horse—the kind of control available with reins, bridle, and bit—is not a given; it is something that has to be created through equipment and understanding. Reins solve this problem by creating a mechanical pathway: from the rider's hands, down the reins to the bit, and through the bit to the horse's mouth and head. When a rider adjusts the length or tension in a rein, that adjustment travels down the rope or leather almost instantaneously and creates a change in pressure or position on the horse's mouth, which the horse can feel and interpret.