Here is a neat way to construct this kind of bridle.



It's just one piece of wire (I think about 2.5m is a good length) with a piece of a thimble clamped (with a vice) in the middle to give the rope something bigger to bear on. The thimble is a large one designed for 4 or 5mm wire - the centre part is cut out to get the desired radius.

I have wondered if it would work without even bothering with the thimble. It all depends on how the rope handles being tied around the wire.