Driving saddles generally have trees just like riding saddles. It's very important that the saddle not be placed too far forward. It will affect the movement of the shoulder. I find most drivers that have come from a riding background really want to put the saddle too far forward.
The saddle should sit a solid hand behind the shoulder blade:
The girth should hang straight down from the saddle and be about 4 fingers behind the elbow so it does not affect the movement of the elbow; the elbow needs to move without being knocked by the girth.
The girth need not be tight as well. Especially because driving saddles are not carrying weight like a riding saddle, they do not need to be tightened down. I always say a hand between the barrel and girth is good.
Hope this helps with understanding how saddle placement should be!!
Very good information! Have a little question/dilemma… My Arab seems to have her withers “set back” a bit more, than my Morgan and her girth area seems small and is more forward of the back of the wither… I know sounds weird… but when I put the saddle on and girth her the whole saddle sits a bit of an angle… and then when I try to girth her to keep it all straight.. the girth of course slides forward and then is to loose… but if I tighten her there where it wants to go… this is where the whole saddle/girth combo “ride” on an angle… and I’m pretty sure the saddle should lay straight and balanced … AN…