Wow, cool site. Just found it a couple weeks ago. I bought a '79 Invader in the fall of 1981 and have owned it ever since. I'm now 60 years old but still lovin' the fact we finally got some snow in central Indiana this year. I was going to post something on here and see if anyone else had this experience. My Invader experienced rapid hyfax wear also. I was aware early on that Kawasaki had recalled the tracks with the metal bars embedded in the track and replaced them with fiberglass. Apparently a few injuries occured when the metal bars separated from the track. Anyway, I discovered that the rear suspension rails were too narrow for the track clips. The rails were not centered on the track clips like they should be. I measured the distance between track clips, and this was identical to other sleds I checked. I looked at the possibility of altering the rear suspension to widen the spacing between rails, but never did. Long story short, a few years later I had the opportunity to get 2 sleds that had been sitting in a barn running so the owner could sell them. One was a nice '81 Intruder. I measured the suspension, and lo & behold the rail spacing was perfect, so guess what...I put the ''81 Intruder rear suspension in my '79 Invader and the hyfax wear has been as GOOD AS ANY OTHER SLED I OWN..Yamaha, Ski-doo, etc. The track on the Invader has the identical distance (width) between track clips that my '83 V-max and '97 MXZ have. The '81 Intruder suspension was identical in every way to the one that was in the Invader, except the rails were now about 3/4 inch further apart and now were perfectly centered on the track clips. It's been a lot of years, but wondered if anyone else had encountered this. By the way, the Invader is still running perfectly and is a blast...also have a 1975 SnoJet Astro SS. Just gettin' started checkin' out this site..seein' lots of great info and pictures.