I had a pair of 2008 KTM Fork Protectors (P/N: 7800109400030
) laying around the garage and noticed that they fit the stock X-Challenge forks perfectly. They offer a bit more protection since they wrap completely around the slider, and the brake and ABS sensor lines are mounted in front (versus on the side on the stock units) so that the lines are less likely to get snagged.
They now make a new version
that snaps around the fork slider so that you don't have to remove the forks from the triple clamp to install them. Here is a link
to the description of the snap-on version.
Here are a couple pics of the KTM fork protectors (older non-snapon version) installed on my X.
Don't forget to bend the upper wire cable guide in toward the center so that the cables don't bind at full fork compression: