I now used my new(-ish) protector backpack for Grischa Muni challenge, and a few rides, so when I was bored on the train, I wrote this little review. It’s a Camelback K.U.D.U. 20 (no affiliation with the brand).
20l is a good size for me, enough to bring a jacket, water, tools, spare tube and a bit of food, and enough different pockets to keep them organized. Could probably go a bit smaller, but you can tighten down the compartments enough for it to not be an issue.
It took a while to figure out which of the 3 (three!) straps at the front needs to be tightened how much for me. But once I did, it doesn’t noticeably move around on my back, and the weight is very nicely distributed between shoulders and hip.
Now, the best feature (for me): integrated back protector. We all accept some risk of injury when riding, but I think the two part I would like to protect especially are my brain that’s why I wear a helmet for Muni), and my spine. Nothing will protect you 100%, and even with the best safety equipment, common sense is still the most important part of not getting injured. But I think a back protector could really save my ability to walk by keeping rocks out of my spine one day, so I think it’s a good addition to my safety equipment.
The back protector is detachable from the rest of the backpack, which I tried out for the first time today. It made me much more comfortable with rolling after a bail (compared to with a backpack, or without a protector) and also is barely noticeable on my back. I wasn’t so shure on how secure it would feel without the “bag” on it, but it stayed in place really well.
Other cool things: easy to strap a helmet to, phone pocket on the hip strap, provision for a drinking bladder (I don’t use one, but if you do, that’s probably nice).
Overall, I’d recommend it (although durability is yet to be proven.) I haven’t heard anything particularily bad about Camelbak products, so I’m not concerned