Bent aluminum stays?

Maybe I just need a pack that fits correctly?

Most important. Can’t adjust if pack doesn’t fit correctly.

The only way I can bend (reshape) the stays in my McHale packs is remove them and then use a rounded fulcrum point to force the stays to change shape. This how stays should work. If yours bend while making simple pack adjustments, well, as Bill Engvall says, “There’s your sign.” That is, the stays can’t work properly.

Yes, if the stays are changing shape under load it’s because they’re not properly fit to your back.

It takes knowledge, time and patience to adjust stays correctly. Done right, a pack’s fit can be a revelation. Done badly you’re better off with a fit’s-all pack off the wall at REI. And, of course, that’s the reason all the big makers got away from customizable stays and went the fits-all route. God Bless McHale, ULA, etc., for staying with the high path…

Uggh. Now I have a new nightmare – forced to choose from new hiking shoes I’ve never seen before, or new backpacks I’ve never seen before. Not sure whether I’ve bought more models of backpacks or boots & shoes over the decades.

As Nick said, backpack fit is critical. HMG makes packs in four sizes. And their aluminum bar stays don’t get mangled – because there are no load-lifters to twist them. Tricksy hobbitses! Love my Precious, uh, Windrider.

But many people are addicted to load-lifters. Maybe you can substitute thicker aluminum stays, or add thin ones as reinforcement, and don’t pull too hard on the load-lifter straps.

— Rex

If the stays are bending, then you are probably well past the intended weight capacity of the pack and/or the stays are not installed correctly as others have suggested.  Sizing up might just exacerbate the problem, since then the stays have to carry even more load if the weight lifters are working as intended.  I’d verify sizing with a lighter load and with stays bent back to ~their original shape before ordering a larger one.

I have several SMD packs and I’ve found their customer service to be very good.  Have you reached out to them with questions about your specific pack?  My Starlite has two aluminum stays like you describe but I’ve never had a problem with them.  My Swift has a U-shaped stay and I don’t know what the Fusion has for a frame (I bought it on Gear Swap for a friend to use on a trip).