new to backpacking and picked up a used arcteryx altra 75 regular size pack. I have fitted it by measuring according to what I have read and vids. Pack feels pretty good except it feels like the most pressure spot is on the top of my butt. I might add that I am 58 and have no hips. I cinch down the belt real tight and most of pressure is off shoulders except in the front of shoulders, maybe I have them too tight. Any ideas or is this how a pack should feel on my upper butt. I have the heavy stuff in the middle of the pack also.
Thanks for any help.

Sometimes before buying used it is a good idea to try on a new pack of the same model if still on the market. If it doesn't fit well you don't have to invest the money on the used one. Packs are as individual as folks themselves. I had the very same problem with a couple brands of packs when shopping last. Someone here may have advise on adjustment to overcome your problem but IMO sometimes torso lengths, body shape ect. are just not compatible with some designs where other designs will fit like a glove. I find a good fit comes easily and you know it the minute you put your load in it. Hopefully you will be able to get a good fit.

Good luck, jimmyb

Thanks for the reply. It feels pretty good. I just wonder how much I should feel it on the upper part of my butt and if that is normal?

I don't have the same pack, but I don't believe I felt such pressure.. Could be the design of the pack has something that pressing on it.

In my opinion, a pack should not ride heavily on the upper part of your butt. A pack of the proper torso length with the proper hip belt will transfer much of the weight to the top of your hip bones with little to no weight on your backside. Arc'Teryx packs are designed to carry the load on your hips not your butt. It sounds to me as though the torso length of the pack you have may be too long for you.

Try this: Empty the pack and put it on. Tighten the hip belt so that the weight is resting on the hip bones with the shoulder straps loosened. The hip belt should cup your hip bones. Tighten your shoulder straps enough that they would control the sway of the pack if it were loaded. Next, snug up the load-lifter straps. Now, have someone look at the load lifter straps. They should be at about a 45° angle as they rise from the shoulder strap to the pack body. If the angle is steeper (60° to 70°) then the pack is probably too long in the torso; if it is a shallow angle (10° to 30° or more) then the torso length is likely too short.

You can measure your torso length easily at home: Loosen the belt of your trousers and lift it to where the top of the belt is even with the top of the iliac crest (the high point of your hip bones) and everywhere parallel with the floor. Bend your head forward and locate the prominent bump on your spine at the base of your neck. With your chin down, measure the distance between the high point of the bump and the top of your belt using a cloth tape and maintaining contact between the tape and you along the spine. For Arc'Teryx packs (according to their website) if you measure 16"-18" you take a small, for 18"-20" you are a medium and if you measure 20"-22" you need a large. Not all pack makers use the same sizing. For example, ULA uses Sm = 15"-18", M = 18"-21" and L = 21"-24". The pack you have should be marked for size somewhere. The ULA web site has a video on measuring to fit a pack http://www.ula-equipment.com/product_p/circuit.htm#Header_ProductDetail_ExtInfo_span

Also, the hip belt has to be of the right size to work with weight transfer. If it is too short, the meat of the padding will not reach the critical iliac crest. If it is too long, you won't be able to tighten it enough to effect weight transfer. Arc'Teryx should be able to provide a hip belt of the proper size if the one you have is wrong.

Just because a pack is comfortable around the house or around the block does not mean that it is optimally fitted. Take whatever time is necessary to be sure whatever pack you have fits. Moreover, make sure that it fits with a properly packed gear load; sandbags are a poor substitute. And, if the pack you have now doesn't fit, get one that does. There are few things in life worse than 40 miles to go with a poorly fitting pack although 40 miles with poorly fitting shoes is right up there!

The general recommendation is that you get your pack last so you know that your gear fits into it with enough room left for food and water and little extra room. Gear (and weight) tends to expand to fill the room available

Thank you for the excellent write up. I called Arcteryx and they directed me to some documentation on their packs. I have the right size. However, I discovered something. When I first got the pack and loaded it up I noticed that the curvature of the inside of the pack was such it was curved in where my shoulder blades would be. I figured that is just the way it is. Turns out that there are 2 aluminum bars that need to be shaped to the contour of my back. The contour of my back is just the opposite of the way they were bent. So I have bent them correctly. The upper straps above the shoulder straps, I was tightening them down too tight and had the wrong angle. I think having the back contour bars wrong added to this problem. I have loaded it back up and it felt much better but will not really know for sure until I go for a walk which I am going to do this evening. I agree a pack that is uncomfortable for a 3 mile hike is not what I am looking for. I am hoping I can get this worked out because it is a nice pack. But if it isn't comfortable for me then it will be for sale real soon. Thanks guys for all the help.

If you still feel pressure in front of your shoulders, see if the point at which the load lifter attaches to the shoulder strap is adjustaable. If it is, play with it - start by moving it back a touch. I prefer it just above my collar bone, but not quite to the high point of my shoulder. That will also affect the angle.

I don't have much to add except that pack fit is almost as individual as shoe fit. It's best to acquire the rest of your gear and take it to the store to fit the pack. I keep saying it's "fit, fit, fit." The pack has to fit you, has to fit your gear and has to be comfortable for you to carry with the gear inside. You don't have to buy a pack in a store, although I'd recommend going through a fitting from someone who knows what they're doing just so you'll learn what a comfortably-fitting pack feels like. If you buy second-hand or order through the internet, make sure you can return it, and go through the same fitting process (with your gear, and hiking around the house for several hours) while it's returnable.

There are several brands of pack that I can't wear at all, especially the much recommended Osprey brand--their hip belts just do not fit my hips so are very uncomfortable.

Thanks again for the help. I took my pack to REI yesterday. They said they could help me. The guy that was supposed to help me really didn't seem like he wanted to help much, but he did try. He said maybe I was wearing the waist belt too high. Did some of the adjustments I have tried over and over. I also tried a couple of their other packs and to be honest mine felt the best. Thought I might like the REI 85 but it was very uncomfortable and felt cumbersome. Anyway went for a hike yesterday afternoon with the waist belt wrapped lower around my hips and it felt ok. However after I got home my hips were very sore. Maybe I am just a wuss. Gonna try some more variations of adjustments. If there is anyone located in the Northern Kentucky/Cincinnati area that could help would be great. Again thanks for all the help guys.

That would be me.

I live in Centerville, about half an hour up I-75 from Cincinnati. I'd be glad to meet you in Miamisburg (on the opposite side of 75 from Centerville) at Great Miami Outfitters. It's a great shop with a good assortment of gear and a staff that is a lot better than REI's.

Send me a PM and we can work out details.

Thanks I will let you know when I can get away. Very nice of you. I also was not aware of them.

One thing that hasn't been discussed much in this thread is pack weight. How much weight do you have in the pack? If you are putting 50 lbs on your back, there isn't much you can do to make it feel good.

Maybe only 30 lbs. I have been adjusting it and it feels pretty good. I have also realized that while hiking I may have to adjust it periodically.

Don't say maybe. Weigh it.

Ok Lori, I weighed it and I was off by 4 lbs. It is 26lbs.
Thanks for your reply and advice.