i have a kelty cosmic down 20 bag (~$125) in a small sea to summit event compression dry bag (~$35) in my viscacha with a fair bit of space left for clothing.   i have been warm in a bivy on a thermarest trekker wearing thin layers at 32F and i think i could do 20F with a little more clothing.

I am experimenting with my Revelate harness packing things up and looking at how things fit. I am wondering what the minimum tire clearance between my dry bag and my front tire should be. I have about 2 inches right now with a fairly large load and that looks tight to me.

How much clearance do you have and what is not enough?

i don't know if you are running a suspension fork or not but if you are 2" won't do and if you are not then its still tight based on my experience.  unless your load doesn't sag or bounce at all as BadA suggested.

you could slide a thin piece of plastic like a cheap cutting board under the straps of the harness to protect the dry bag where the tire would contact in case you do get the odd rub.  i am dealing with this issue on a size small 29er with a negative rise stem.  its a challenge getting clearance with even a smallish handlebar roll.

Looking for a handlebar harness in excellent shape.  Prefer a Revelate as I have a pocket to attach but would consider anything.  Would also consider a Sweet Roll type bag.

Cash or trade for parts (I have a couple BB7 brake sets, thomson posts/stems, etc let me know)

Thanks!

what size is the sweet roll?  will you sell without the pockets?

not sure how close you are but according to the REI website the Denver flagship store has relevate sweet rolls and large pockets in stock.

what size frame is the soma juice bag for? 

i have a thomson 30.9 post i would trade or sell but yours is likely for the bent top tube and mine is straight top tube from 2013 so it wouldn't work would it?