You have to be really careful with neoprene. When it's dry, some horses will freak when it pulls their hair.
I only use mohair string girths. They have some give, they are soft on the skin, and they don't sore a horse for no reason. I train horses for a living so I spend hours on them daily. Don't have a problem with sores or slipping.
As for measuring (Maureen, your link didn't work for me, it brings up the site, but the page itself if blank), the way I do it is this: I put the saddle on with a pad the way I'm going to ride. I run a string or small rope around the girth where the cinch will lay and up through the D-rings that the cinch will attach to. I pull the rope up snug and mark it at the D-rings. Then I measure between the marks (the part that was around the horse), subtract 16 inches (to give 8 inches of latigo room on both sides) and round down to the nearest increment of 2.
For example, if I measured and there was 45 inches between the marks, then I'd subtract the latigo room (16") and get a cinch measurement of 29, but cinches are only mass-produced in 2 inch increments. So, in that event, I'd likely go with a 28 because horses will generally get smaller the more you ride them and if I went 30, it might end up too big. Plus, mohair cinches will stretch out a bit when you first start using them.
Last edited by smrobs; 06-13-2013 at 11:28 AM.
Reason: my math didn't calculate correctly LOL