Thursday, May 25, 2023

Ultimate Direction Fastpack 40L Review: Tuscany Trek Tested!

Article by Dominique Winebaum

Ultimate Direction Fastpack 40L ($195)

Over the past year I have tested a collection of technical apparel from Ultimate Direction for running and hiking, however, going with a UD pack on a multi-day hike was a first – and a game changer! 

From the start I shed a few pounds from my load by using the UD Fastpack 40L, a mere 1.6 lbs /714g versus 4.4 lbs for my usual ‘trekking” backpack, a Mammut Trea Spine 35L which I tested back in 2019 when hiking 200 miles on the Via Jacobi in Switzerland, and which I used again for the Tour du Mont-Blanc in 2022.  

Features & Specs:

  • Pockets: Large front storage for water, phone, maps, glasses, or food, easy access pocket with key fob, large external stretch mesh pockets for quick access, and two large side pockets for larger water vessels

  • Unique zip-down main compartment for total access to gear with roll-top closure expands or compresses to secure varying capacities

  • Sliding rail sternum straps and removable and height-adjustable T-hook waist belt for heavier loads

  • MonoRip Mesh is very strong, but extremely breathable

  • Daisy chains for securing extra gear

  • Volume: 2502 in3 / 41.0L
  • Dimensions: 19.5" x 11" x 7.75" / 49.5 x 27.9 x 19.7 cm
  • Weight: 1.60 lbs. / 0.715 kg
  • No. of Exterior Pockets: 15
  • Reflectivity: Yes
  • Reservoir Compatibile: Yes
  • User Chest Size (S/M): 25 - 40" / 64 - 102 cm
  • User Chest Size (M/L): 30 - 48" / 76 - 122 cm

Yet, I wondered how my loaded UD Fastpack would feel on my back and shoulders given the lightweight frame as I needed enough clothing along with a change of footwear for our 5 days/75 miles walk/hike on the Via Francigena, from Lucca to Siena, with sightseeing on both ends & two traveling days by train. And yes, I tend to overpack!  

Despite the weight of my loaded pack, at 18 lbs / 8.16kg , I experienced zero issues with shoulder pain, nor back pain, during our five-day walk.  Distances between towns/cities were long for the most part with mileage ranging from 14 to 19 miles, but for one short day (8 miles).  The weight-to-capacity ratio of this lightweight Fastpack is optimum as described in the specs.  Tuscany by foot is a great way of discovering this beautiful region, albeit a bit arduous, and for sure my UD Fastpack 40L made it easier to carry my own gear. 

We met a hiker from Scotland wearing a UD pack, a 20 L which she had purchased to participate in the Marathon des Sables a few years back, but without finishing due to the extreme heat in the Saraha desert.  

We took note that her pack was too small for the multi-day trek on the Via Francigena as she complained that her shoulders were hurting from carrying the pack, which she had “supplemented” with an oversize front pouch.  Also, take a look at her protruding bottle and lack of a waist belt on her 25L UD pack in comparison to mine.  Sizing matters! 

The size of my tester is a S/M 25-48 inches for torso, which worked well for my height at 5’5”.  My husband, Sam, used an older UD Fastpack 35L. Adjustable straps are plentiful on the pack for a secure fit.  The UD Fastpack 40L has three straps in the front with the lowest one, a T-hook waist belt, especially designed for heavier loads.  I secured  my pack with all three at all times in order to keep everything comfortably in place. 

UD packs are all about pockets, front, back, and on both sides of the pack, small and big, that are easily accessible.  

Notably, this newer version has a total of 10 front pockets lined up on the shoulder straps, with two large ones holding securely each a 500 ml water bottle, four small divided pockets for storing gels and small items, along with two lower pockets big enough to hold my iPhone 14 and a pair of glasses.  In addition, there are two side zippered pockets underneath the two lower pockets to safely stow away flat items, such as keys and credit cards, but which are too small for a phone.

Straps over the front pockets are designed to store polls, so indeed, to maximize the capacity and use of the front pockets, take the time to study your options for storage before packing. There is even a yellow safety whistle which stows in its own pocket seen above just below the white water bottle.

Admittedly, I made use of the front pockets mostly for my water bottle as I used a neck pouch to store my phone, glasses, and money.  We were walking at a regular pace and steadily, but not fast, and we could afford breaks along the way in cafés and bakeries, so we would refuel with real food. 

I made very good use of the two back pockets, a large expandable one and a smaller zippered one, along with the two side mesh pockets.  I tried to control the height of my pack by putting more items in these three pockets, including at times, my recovery shoes.  I absolutely loved having so many pockets, front, sides, and back.  

The Fastpack 40 includes a full single side zip access so you do not need to unroll the top to access the main compartment. Sam's older version does not have one.

Inside we have a reservoir pocket towards the back. Sam used it to store his laptop. There is also an internal sleeve one can use for a tent or small sleeping bag.

As a roll top pack you can expand its height for more capacity as I did for the trek or bring it down to turn the Fastpack40 into a daypack size carry as shown above.

I prefer drinking water from a bottle than a reservoir so I did away with the latter, especially as I would refill my bottle with fresh water along the way.  For my next trip, I plan to invest in UD soft flasks and bottles armed with straws, so I don’t have to pull my water bottle each time I need to drink.

The rear of the pack has many daisy chain loops along the black reinforcing webbing (Sam’s earlier version had none) and ice ax type loops so if need be all kinds of things can be lashed to the rear of the pack such as sleeping pad or laundry to dry.

The back panel of the UD Fastpack has been upgraded with Infiknit and FastFlow technology to increase breathability and moisture wicking.  I never experienced a sticky back wearing my UD Fastpack despite hiking in the heat – optimum breathability and moisture wicking with this back panel.

We encountered heavy rains on our last day and we wished our UD packs were equipped with a rain cover as most hikers on the trail had as they are not waterproof in any kind of sustained rain. Sam has a removable one in a zippered bottom pocket in his Camelbak Octane 25L and it weighs next to nothing. In fact UD says the following about the pack mesh: “MonoRip Mesh is very strong, but extremely breathable.” 

I kept my belongings in a large trash bag inside my Fastpack, yet a rain cover would have kept my pack dry.  

I have since purchased a rain cover along with a dry bag for future treks.  I am lending my UD Fastpack to my daughter, Hannah, who will be trekking from Verbier to Zermatt on the Walkers’ haute route in August. In addition to the rain cover and dry bag, I am planning to equip her with two UD “Body Bottle” 500ml. It will be just the right pack for her, especially as she is the type to fast hike if not run the hike.  Stay tuned for Hannah’s feedback and pics!

I was also grateful for my UD Ultra waterproof jacket seen above which I tested last year (RTR Review) along with my new Velum skirt (review to follow).  We also have an RTR review by ultralight backpacker Markus Zinkl in Germany of the smaller capacity UD Fastpack 20 here.


I can honestly say that my UD Fastpack 40L exceeded my expectations as the only drawback was the lack of a rain cover, which is easy to remedy.  I experienced zero issues with the weight of my Fastpack with 18 lbs though I reminded myself that next time I should pack less.  In comparison to my Mammut Trea 35L, which had no external pockets and is much heavier, the UD Fastpack 40L with a total of 14 external pockets (plus the internal reservoir pocket) and is lightweight as they come, was truly a trekking game changer. 

Shop for the Ultimate Direction Fastpack 40 at our partners:

Ultimate Direction HERE

Amazon HERE

Dominique has run for over 40 years, consistently about 25 miles per week at paces between 10 and 11 minute miles and once a week down in the mid 9 minute miles. She races rarely, but always surprises more hard core runners in her age group when she does. She has a 1985 marathon PR of 3:16 in her second marathon which at the time put her on the top 10 Swiss women’s lists. She is the mother of two grown children, both runners post college, and also enjoys nordic and alpine skiing, tennis, hiking and trekking, and gardening. 

Samples were provided at no charge for review purposes.RoadTrail Run has affiliate partnerships and may earn commission on products purchased via shopping links in this article. These partnerships do not influence our editorial content. The opinions herein are entirely the authors'.

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Ante said...

Great review! Two questions,
which model year is the pack?
What hats are you wearing?

Nulls Royale said...

Great review. Could you specify more about you packs?