For what it's worth, from the RPS Owner's Manual, page 42:
4. Turn both adjusting nuts the same amount of turns until you have reached the correct slack. To tighten the chain, turn the adjusting nuts clockwise. To loosen the chain (provide slack) turn the adjusting nuts counter-clockwise. Adjust the slack in between the drive sprocket and the rear wheel sprocket. Move the bike forward, stop and park it on the side stand. Recheck the slack, it should allow vertical movement by hand:
9/16 inch (15-30mm)
From my own experience, I now believe this. I didn't think this was correct from my ancient dirt bike experience and everything else I read. However, it also demonstrated to give the owner's manual the benefit of the doubt over the internet. When I did my first adjustment - I set a little extra slack, 1-2" because that just seemed more logical. I quickly found out that wasn't a good choice. Chain jumped, cracked my front sprocket cover (17t front, so no space), and carved up the rear axle area a bit. Luckily it didn't break, and it's been holding up good enough after getting readjusted to spec.
I do think you'll want to err on the side of tightness if you stay with the stock chain.
They have a couple of pages dedicated to maintaining the chain in the owner's manual. Here's a link if you didn't get a paper one included:
http://therps.net/User%20Manual/Hawk...s%20Manual.pdf