black diamond rpm or golite ion??

For that kind of weight the Ion isn't even relative. You should be looking at a Jam2 which compares better to the RPM but will be more durable and is slightly more feature rich.

Kevin, I wouldnt really call 20-25lbs ultralight. With a bad back you migh try a pack with a real hipbelt. I use a Osprey Varient 28. It is listed at 1700ci 0r 28 L but seams to hold more, I would guess 30% more than my Ion. This is my expedition pack and I use it when carrying heavy laods. Its minimun weight is 1 lb 13 ounces or 2 lb 5 ounces with its top lid. It is very strong kinda light and has excellent load distubution. If I was trying to protect my back I would put more weight into some form of proper suspension and save the extra pound somewhere else. Just a thought but I have been there and find it to be a small sacrafice to save the back. Good Luck Ali

thanks guys forthe replies itlooks like im out of
on getting anything that light to fit my needs

my back is in good enough shape to handlebackpacking as i didn t have any major surgery
on it just a microscopic procedure i can still carry weight/work/walk and all of that i have no pain or anything i just wanted to lighten up so that i dont have to
worry about problems later on
that osprey packlooks good and another one that looked good too was the mountainsmith needle i think its 2lb 12 oz
anybody know anything about them i know my other mountainsmith packs are great quality very well built
packs something in the 2-2 1/2 lb range would be awesome
i can get the needle for 59.99 or the osprey for 109.00
any other suggestions for this price range?? i would like to stay under $100 if possible
thanks guys