Hey guys, I keep snapping the flying wires on my Ultimate (tail). It only happens to the ones on the top, and it usually happens aftter I tighten them.

I'm not making them "piano" tight, just making them so they aren't "sloppy".

They are breaking at the loop at the end of the wire, where it goes through the fitting that screws into the clevice.

Any opinions on why this may be happening?

Cold be a sharp edge on the fitting...

Could be that you are overstressing the wires with the downforce on the tailplanes. If its this one... where's the CG? How fast are you flying? How "hard" are you pulling for the loops?
Pulling too hard for loops at high speed will put a HUGE stress on the tailplanes and they can try to flex... and thus snap the wires (which would mean the wires saved the airplane... by taking some load and preventing the tailplanes from snapping.)

What material are you using for the flying wires?

I don't fly very fast, half throttle or so usually, except vert..

The wires are plastic coated steel "leader" type and the only place they break is at the loop.

It could be the sharp fitting suggestion. Maybe I take an old piece of wire and use it like a file to wear down the edges.

Maybe you have them to tight?