How would the stirrup the bit and horseshoe have affected communicationsby A.D 500?

The bit ( earliest form to date precedes 3500 BCE), The Stirrup (Earliest form from around 2nd century BCE), and the horseshoe (Earliest known form from around 100 BCE.) Would have allowed populations to travel further and faster thus spreading languages and how humans communicate across vast areas.

The stirrup in the earliest form was just a toe loop, but eventually morphed into the modern stirrup. This allowed riders to sit for longer periods due to better balance fro the stirrups. With better balance the riders would not get as fatigued during long travel.

The bit, first made out of leather, sinew, or rope of some kind would have allowed better control and direction of the horse and reduce the amount of work the rider had to do in order to get where they were going.

Horseshoes, though not necessarily needed back then allowed horses to travel over terrain they were not familiar or acclimated to, keeping them from getting injured or sore.
All of these things combined meant that the riders could go longer and further than previously able to on foot. This allowed for mail such as letters and declarations of war, peace, or surrender to be sent at a much faster pace. This helped to form the countries and languages we have today, it is true when historians say the world was conquered and built from the back of the horse.