This could be partially due to weight distribution (side to side). However, I found the main reason an X boat acts differently on a port tack than a starboard tack is that the backstay is mounted on one corner of the stern. Under moderate wind, if you look at the top of the mast on one tack, it is held fairly straight by the backstay on one tack. On the opposite tack, you can see the top of the mast bend off to the lee side and the backstay loosens up.For some reason mine seems to like it better on starbord tack also. I don't really know why. I wouldn't think it would have anything to do with the lateral imbalance because I move people around when sailing to keep the boat at a comfortable angle.
So, every time you tack, you have to re-adjust the mainsheet.
Now, if you split the backstay it will now pull straight back and there will be a lot less re-adjustment of the mainsheet form one tack to the other.
To do this, you must install a chainplate in the same location on the opposite side of the stern. Then you can make a new stay about ten to twelve feet long. Attach each end to the two chainplates Use a shroud adjuster, turnbuckle, or small purchase (similar to a boom vang) on one side where it attaches to the chain plate. Cut five or six feet off the original backstay and install a wire block on the new end. Your new short piece will run through this block and when the purchase, or turnbuckle, or whatever you used is tightened, your backstay will, in turn tighten and center itself.
The small effect the backstay has on the X rig, will now be equal on either tack.
Once again, I'm no expert by any means. I'm only sharing what seemed to work for me.
Best Breezes,
Steve K.
