Zerk 13 UL Daypack w/2L Bladder

The Zerk 13 UL is a really nicely designed pack. Very spacious storage with lots of useful and well-placed pockets. Water bottles can be mounted on the shoulder straps which is essential for me. Very comfortable pack too!

I'm not a biker but I was searching high and low for a daypack to take on my upcoming group tour of Vietnam. I was struggling to find the right volume of pack. They all seemed either too big (18L) or too small (10L). I had never heard of Mountainsmith. I found my bag brand new with tags still attached at a resale store for about half price. I'm not planning to use the hydration bladder on this trip so I was searching for a tall and kind of narrow front netted pocket for holding my 40 oz Hydroflask during our daily activities. Our tour operator provides us with regular access to filtered water to fill water bottles. In my experience, water bottles always are tipping out of side pockets on backpacks! This one is so perfect and I can support it a bit with the exterior cord. The front chest pockets are amazing and a unique feature for a backpack. I can fit my iPhone 17 Pro Max + case in one and might put some bathroom supplies in the other (tissue, wipes) for easy access. I wanted my phone to be safe from phone snatchers (so not constantly in my hand or hanging out of my pants pocket), but also at the ready, as I take a lot of photos. Those three pockets are what immediately sold me. It took a lot of wrangling, rethinking, and adjusting but I think I finally got this pack to fit correctly on my petite but curvy frame. This backpack is also big enough to take on the plane as my carry on, since I'll be checking my main suitcase. I did a trial packing run and fit a change of clothes/ underwear/ socks/ pajamas in a compression packing cube. I'll be able to fit my device chargers and essential medications and toothbrush as well. Once I'm reunited with my suitcase, I'll keep all that stuff in the suitcase and use the day pack for a sun shirt, hat, sunblock, mosquito spray, water bottle, phone, etc. I wish I could find a really good overview video of the backpack and all its features/ functions/ adjustments (something more detailed than this one) because I’m probably missing something. It would be helpful to see the backpack on a woman’s body, as we are built differently!

So many pockets! The pack is very comfortable to ride and hike with. I’m not a fan of hip belts when riding, but this one works great; it positions the pack weight where it needs to be. I forget I’m wearing it. Each element of the pack was very well thought out.

amazing room for multiple burritos and the correct amount of water to be lugging on your back while pushing pedals around the map. love the securness (its a word now) of the three clip straps, the depth of the shoulder strap pockets going vertically down the torso and how handy the flank pockets are at the bottom of the shoulder straps. The magnet to hold the water hose is a complete game changer. no more fighting with the ridiculous clip that played a part in my last wreck. I cannot recommend this backpack enough for getting out there!!!

Most comfortable backpack for all rides!