I used to ride 180mm triple cranks [Race Face Turbine LP] and enjoyed them quite a bit. They're not that tough to spin, but it helps if your legs are long. For the SS rides in my neck of the woods, I don't think I'll be doing much spinning anyway, just lots of grunting when I climb out of the saddle. I'm looking for a SS XC crank as well, but I'm avoiding the DH stuff because it's heavy and most of those cranks seem to come in 170. I was going to get the Truvativ SS crank through Pricepoint, but they sold out.