How to get horse armor in zelda breath of the wild: to get the ”exquisite bridle” you want to talk to someone at hylian stable and on the obstacle course and get a time of 1:29 or lower.
To get the “exquisite saddle” you have to get a time of 1:20 or lower to get it.
Another way to get horse armor is to catch the legendary white horse and register it at the stable to get the armor for it.