I have difficulties with the curb rein on the double bridle feeling way too short IF both the bradoon rein and the curb rein are the same lengths.
With my MS I developed difficulties keeping the double bridle reins at the proper lengths. I found some bradoon web reins with colored stops. I then searched on the web and found some Warm Blood length notched reins (1/2" wide). With the different length reins I can hold the reins at the same place without affecting the curb bit, with same length reins my curb reins usually ends up being too short.
With a glance I can now tell if I have my hands in the right place on the bradoon rein (those colored stops really help with that.)
The curb rein takes a longer look since it does not have the colored markers, but my fingers can FEEL when the horse takes the curb rein, and the notches help me keep my hands still on the reins. The notches also help me shorten/lengthen the curb reins so they are both at the same length.
It may also help me that I put the curb rein below my little fingers and I have the bradoon reins going between my little and ring fingers.
I am riding two different horses in a double bridle with this set up.