On me, the "new" Ohm belt that you think looks small, would barely snug up enough on a 31" waist. (what they call medium) It did, but barely. If I had lost another 2 lbs it wouldnt. Remember, theres a couple inches of buckle in the middle between those wings you see. A 31" waist isnt that big. I know its oval shaped, but if it was a circle it would only be 9.8" diameter. Now envision that hipbelt wrapped around that and you will see what I mean.
And it depends on the pack. The pack isnt rigid if packed for comfort, and as you tighten the belt, it may conform to you and that belt may totally encircle your waist . You will be surprised how much it tightens. I am sure the large would be way too long to tighten up. If you pack is packed up firm, like a balloon, its not going to be comfortable, but the belt will also be effectively shorter on you too by several inches.
you can get a small circuit hipbelt on the OHM2.0, that a MUCH more substantial hipbelt and better fit for 31" waist. Or you could ask and get it with the "old" ohm style even small belt/pockets from a couple yrs ago, that barely covers the hipbones, but will fit your 31" waist better.
