Lightweight and Full Featured
The REI Flash 45 Pack is a fantastic lightweight, full featured pack capable of carrying a thru-hiker load if you can pack efficiently. I have had many packs over the years and each one seems to either represent improvements in technology and/or serve a specific need.
If this link to the REI Flash 45 no longer works unfortunately it may have been discontinued…in the meantime it’s on sale for $64 !
At just over 2-pounds (1kg exactly), it was a nice weight reduction over my 5 year old Flash 55 (which weighs ~30% more), plus the 45 has just enough bells and whistles (litterally…the sternum strap has a built in whistle) to make you feel as though you are not sacrificing functionality.
As far as sizing goes, I would suggest sizing up compared to what most people are used to. I’m 5’10”, 155 lbs with an average torso length and the Large was very comfortable ( medium could have worked too ). If you are a bigger person the large will likely feel to small. An added benefit of sizing up i(f the fits is comfortable) is that the pack grows to 50 liters (per the tag), so it gives you a bit more space.
I used this pack most extensively on a 220 mile JMT through hike. My base weight was 15 lbs and when I added the largest food drop and full water I was ~33 lbs. At this weight the pack was definitely just beyond it’s comfort limit for me. A couple days later when my food supplies had been reduced it was no problem, so I would say to plan on no more than 30lbs for optimal comfort. A typical bear canister (BV-500) fits vertically without any issues but will not fit horizontally (smaller sizes would). The rest of my gear for this trip basically all fit inside the main compartment (and top pocket) …needs to be compressible gear and efficiently packed. The gear I had on the outside mesh pockets were tent poles and water bottle/hydration bladder.
Considering how lightweight the pack is there are quite a few features you don’t typically find… The 2 small mesh pockets on the hip belt are indispensable for things like camera/phone or gps as well as pocket knife, lighter, lip balm. The top pocket holds quite a bit more…perfect for lunch, maps, steri-pen/filter, etc. There is also a small pocket on the shoulder strap which was great for keeping energy bars or sunscreen. Also, the underside of the top pocket has another access compartment (with a key hook). There is a hydration sleeve and hose port inside the pack, but I didn’t find these very useful because a bladder would take up too much room in the main compartment and was too difficult to get out when the pack was full. Instead I used the mesh pockets on the outside which worked great.
The exterior of the pack is basically covered in stretch-mesh, which is common for ultralight packs. The sides have openings cut in them so I could easily access a water bottle or other items while walking… I thought this was a great design feature. The mesh is also a good place to stash a wet tarp or rain jacket for quick access. The hip belt had sufficient cushioning as well as on the shoulder pads (until overloaded). There are lightweight metal stays to help transfer the load to the hip belt, but there is no rigid backsheet. The back panel has cushioning that attempts to provide ventilation without much luck. I also had to pay special attention to how I packed everything so I wouldn’t feel the bear canister through the back panel (sleeping pad strategically placed solved the problem). There are load lifters but they really needed due to the compact design.
Everything seems to be holding up nicely. The nylon on the bottom of the pack shows some wear from setting it on the ground with the hard bear canister on the bottom. A small plastic buckle cracked on the release tab (doesn’t effect usage). The only other issue I had was the sternum strap seemed to keep working it’s way up but not uncomfortably…more of a design flaw.
At the full retail price ($130) this is a great deal and even better when they had it on sale for $80! Comparable lightweight packs that would perform similarly could easily cost $250-$300. If you have, or are committed to getting, an ultralight backpacking kit this pack will definitely handle things well for weekend or longer trips. On the other hand, if you are just starting to go in the ultralight direction I’d recommend buying other gear first (sleeping bag/pad) because this pack won’t handle the volume or the weight.