The saddle was slipping around because I've got the cinch so loose because of the rubbing issue. I've already moved it forward in this pic, and you can see from the sweat here how far back it had slipped. I had his breast collar on, but it's narrow and I don't like it so tight it'd bind on his shoulder when he moves, so it wasn't tight enough to keep it from slipping back. I tightened up the cinch at this last stop, because there wasn't an easy place to get back on if it wasn't tight. He did fine. No rubs.
I may switch back to this breastcollar... It's elastic on both sides so I'd use it a little tighter. I stopped using it before because I thought it looked like it hit him in the neck, but I can attach it to the cinch billits I think, and move it down that way. I like that it doesn't connect to the cinch between his legs. I've been trying to ride with the cinch further back to keep from rubbing, but the breast collar pulls it forward.
