Track direction makes no difference as far as hyfax wear. My guess is that your not breaking in your new hyfax properly. If new hyfax is installed and just run like normal, it WILL melt and fail early.(especially in low snow conditions) New hyfax needs to be tempered to withstand long term abuse. All you have to do is get it heated up with a little riding and then park it in some loose snow until completely cooled. (kick it in there if you have to) Usually one good tempering will do the trick but if you can to do it a couple/few times you should be good to go for thousands of miles. (unless your a mud runner)

Oh yeah, like pockets said, track tension is a big culprit of premature hyfax wear.