Yes the HP4 is a MX tire specifically for extremely hard packed "blue-groove" but the funny thing is that it lasted longer than all the other fronts I ran (~2500 miles before cupping enough to dismount.) I still have that tire on the shelf and had thought about remounting it in the other direction to see if it squares back up... realistically it will just be a spare for one of my tightwad friends! I may still try the michelin desert just so I won't always have to wonder how it works. It can't be worse than the motoz s/t that's on the front now (fingers crossed!) I do wonder if it is very narrow like the "90width" michelin m12 (measures closer to 80mm) I have or if it is a wider carcass like the "90width" michelin HP4 (measures closer to 95mm), it sure would be nice if they would standardize!