Guys don't forget metzlers. I have bout 2,500 miles on my Metz and no sign of an serious wear and I ride hard. My rear is at 46 and front 21' is at 42.

I've done lots of research before getting my tires and I got great feedback bout Metzler tire wear. I would recommend'em.

 

I only got 7k out of my Dunlop 591, Put Avon Storm 2 on which I liked looked wider than the Dunlop picked up a screw at 7500, would have went another 1k easy.. I put a Commander II on now, it run narrow but not as bad as a Metzler... If the Michelin mileage hods up as stated, I'll stick with it, tired of changing a rear tire once a year..

 

I had bout 8,500 miles on my stock Dunlop when i changed it. Probably would have gotten another summer out of them if u didn't do few burnouts

 

Your right, the 502 is a bias, one drawback, it is made for Harley by Dunlop. This means it is a Harley Dunlop and and because it is a Harley tire I can buy 2 Night Dragons for the price of one 502 ($350), even up here where they are both more expensive than down there.
The night Dragon is a bit thinner, but I only have a 1/4" clearance on each side between tire and fender.
Makes you wonder why Harley is moving towards Michelin. I despised the Dunlops and would never waste a dime on them. JMHO

 

Metzlers are also a great tire.
The OP asked about the Night Dragon though.
I bought the Night Dragons because I could not get a Metzler or Avon in bias front and rear. Believe me, I too did a lot of research,
From other posts here, a lot of the riders are liking the Michelin's as well.
I had too many close calls with the Dunlops. From getting caught in grooves in the road and being pulled into opposing traffic to losing the back end due to running out of tire and not sticking to the road.
I ride hard and like the cornering of the Night Dragons. I have lots of confidence in them and will buy another set when I wear these ones out.

Every one has an opinion and experience with a brand of tire of their choice. It all comes down to how you ride, how deep are your pockets, and what are you looking for in a tire.

If you are serious about the Night Dragons, search the forum for threads on them.

By the way, Pirelli owns Metzler.

 

Have been using the Pirelli Night Dragons (front & rear) since last fall - very responsive tire on my FXDC. Got maybe 6000 miles and still plenty of tread (though I made an error on rear shock adjustment and now have a cut on them from bottoming out). Definitely feel the difference from the stock Dunlops. Using stock spoke wheels (with tube) but wanted to use the 180 rear and not all mfgrs have that specific sizing. MC Superstore is running a promotion on them. The attached pic is what I paid last fall (just for your reference). Good luck in your choice.