I have not used a mohair girth with my Ortho-Flex. What I have tried
recently is a Biothane Quick-Cinch from Sportack. My Express Lite has
O-F's forward yoke western rigging instead of the english rigging that is
standard. It came to me like that from the original buyer. The tie
strap was a major aggravation during competition. It took a long time to
uncinch and recinch at vet checks and was a real bother to me. The
Quick-Cinch can be tightened easily with one hand and will cinch up
snugly as O-F recommends. I thought that the Biothane would gall but I
took Janeen's advice and tried it without any fleece or neoprene cover or
lining - just the plain 3" wide Biothane against my horse. It was
wonderful to find that it gets slick with sweat and does not gall even
my thin-skinned Arab at all. And it has the advantages of Biothane such
as easy cleaning with only a garden hose and a sponge...