1. The saddle may not fit the horse right. 2. The horse might be mutton withered. 3. The horse may be holding in air and blowing out his belly while you are cinching, and then when you go to get on the saddle isn't as tight as you thought it was. 4. You may be a little on the heavy side and pulling the saddle out of position when you mount.
A back cinch won't help, all they do is keep the saddle down in the back. Your best solution is a breast collar and a mounting block. But you might want to get your saddle checked by a saddle fitter.[/QUOTE]
Thanks i'll reply in your order.
I had the saddle guy come out and check a short while ago and it's a good fit.
Yeah my mare is very mutton withered and flat backed she is a uk native breed.
I usually move my horses around on the ground to get the feel of them before getting on but she does blow out and I have to re-tighten once I have moved her round.
You may also be right on this aswell i'm afraid to say I am slightly on the heavy side (12 stone) for my height. I do use a mounting block but sometimes I have to get on from the floor when we are out trail riding.
So breast collar would be the way to go then?