Wednesday, May 24, 2023

Ultimate Direction Fastpack 20 Review

Article by Markus Zinkl

Ultimate Direction Fastpack 20 ($149.95)


The UD Fastpack line features packs of different capacities. The line covers 20, 30 and 40 liters and also has a women specific range called “Fastpackher”. UD was nice enough to send me over their 20 liter Fastpack model. The Fastpack combines the running vest style strap system with higher capacity usually found in more traditional backpacks. Over the years more and more manufacturers like Salomon with their XA or Montane with their Trailblazer launched similar style packs. UD was nice enough to send me over their Fastpack 20 to run it through its paces. 

Tech Specs

Volume: 23l

Height: 18.5" / 47.0 cm

Width: 11.0" / 27.9 cm

Length: 7.0" / 17.8 cm

Official weight: 21.4 oz / 607 g

Sample weight: 22.9 oz / 649 g

Removable Hipbelt: 1.6 oz / 45 g

Removable Backpanel: 2.4 oz / 70 g


If I could mention only one thing about the pack it would be features. This pack is packed with features. No pun intended. Let’s start at the back of the pack.

The pocket layout is the same on each strap, except for the little emergency whistle on the left side. Even the emergency whistle has its own little pocket. Starting with the big water bottle pocket. I used it with my standard 500ml Hydrapak collapsible bottles, which are a bit tall, but weren’t that  big of a problem bouncing around. The bungee cords with quick release locks helped securing the bottles. UD also offers a bit wider and slightly less tall bottles, which would fit a bit better. 

On the outside of those pockets there is an additional pocket separated in two compartments. I used it for smaller items like sunscreen, a chapstick or gels. Even sunglasses fit in it. 

Below that there is a bigger pocket for bigger items like gloves, a beanie, a buff or additional nutrition. I could easily fit 6-7 Clif Bars in there. All mentioned pockets are made out of stretch mesh, which makes it easy to fit bigger items in them. On the side of the large bottom pocket, there is a zippered pocket, which is supposed to be for your phone. I found it too small as a phone pocket. I lucked out since my Zenfone 9 is one of the last small smartphones (146.5 x 68.1 mm or 5.77 x 2.68 in). Every other slightly bigger phone will not fit. Also the other stretch pockets are not an option, because they are not secured, which will cause your phone to bounce around and probably fall out. On the side of each strap there is also a running pole attachment to secure it on the side of each strap for easy access. 

The pack also got two side stretch pockets for additional storage. On each side there is a compression strap, which ends with a buckle to close the roll-top closure. In my opinion the last attachment is sewn too high up on the pack, so you can’t really tighten down the roll-top when it is not loaded to the brim. So I just unclipped it there.

On the side, running down from top to bottom there are also multiple loop attachment points. 

Attached there, on each side, there is also the second pole storage option. 

On the back there is also another big mesh stretch pocket to easily access items like rain gear etc. The pack also has got a zipper running down from top to bottom in order to access the inside without opening the roll top closure.

Sizing and Fit

UD recommends the following sizing:


Torso (in)

Chest (in)



26 - 39



36 - 48

I went with a size M/L which fits perfectly for my 19 in torso. So I would recommend sticking to UD’s recommendation above. The fit is very good. The relatively stiff backpad spreads to load pretty well and if you are using the hipbelt it transfers the load really well to the hips. 

My only gripe was the stiff adjusters for the two front chest straps.

After 5-6 six hours they dug into my collarbone, which made it a bit uncomfortable.. Besides that, the pack allows a very customized fit. The chest straps are adjustable in length and position. The harness is also height adjustable. It uses T-Hooks so that you can change where the harness attaches to the pack. This really allows you to dial in the fit.


The pack performed great for me. Due to the dialed in fit, it rides really well on my back with minimal bounce during running, even with heavier loads. The good fit also hides its weight really well. At over 22 oz it is quite heavy for a 20l fastpack. I personally would have liked it to be a bit lighter. Some features such as the heavy straps and stiff back panel are overbuilt for what it is. This makes it incredibly durable though, considering also the excellent build quality. My only real dislikes were the stiff chest strap rail, which made it quite uncomfortable after half a day, and the press buttons on the front pole storage, which made it really hard to open.

You also have to keep in mind that the pack is not water resistant in any way. The seams are not taped and the big zipper is not waterproof. This is no big deal though, since almost all packs are not really waterproof. So I pretty much always use a pack liner to keep all my stuff inside the pack dry. Of course you can also use some dry bags inside your pack.


Overall, I’m really pleased with the pack and I will continue using it for shorter trips. Personally, I would like to put it on a diet for the next iteration and solve the stiff chest adjustment rails. If you are in the market for a feature packed adventure pack for shorter trips, the Fastpack 20 definitely will not let you down. For a fastpack it is built like a tank and definitely will not fail you on the trail. If you need a bit more capacity, it is also worth checking out the bigger Fastpack 30 and Fastpack 40 (RTR Review soon), which offer 30 and 40l capacity respectively. 

Fastpack 20 and other UD Fastpacks are available at our partners: 

Ultimate Direction SHOP HERE 


Backcountry SHOP HERE


Moosejaw SHOP HERE

Markus Zinkl: I’m 33 years old and live in a small village in Bavaria, Germany. I started hiking and backpacking 5-6 years ago. Coming from trail running and with light and fast in mind, I started with ultralight gear. Over the years I tried and tested a lot of gear, always in search of weight savings. Although still trying to stay out of the ultralight rabbit hole. I spend most of my days off from work on the trail, with at least one 2-3 week thru-hike. Among the more well known trails I have hiked over the last two years are the GR221, WHR (Walker’s Haute Route), TMB (Tour du Mont Blanc) and TC (Tour du Cervin-Matterhorn). As you probably notice by now, I’m at home in the mountains. So if I’m not running or thru-hiking a bigger trail, I’m probably somewhere in the Alps checking out some shorter trails.

The products that are the basis of this test were provided to us free of charge by Ultimate Direction. The opinions presented are our own.

We welcome comments and questions in the comments section below.

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.

Comments and Questions Welcome Below!
Please let us know mileage, paces, race distances, and current preferred shoes

Men's & Women's SHOP HERE
FREE 2 Day Shipping EASY No Sweat Returns

EUROPE Men's & Women's SHOP HERE

Europe only: use RTR code RTR5ALL for 5% off all products, even sale products 


Men's and Women's SHOP HERE
  • 10% Savings Every Day*  5% Back in Rewards Cash
  • Test Run Shoes 90 Days Worry Free
  • Crazy Fast, FREE Shipping

Men's & Women's SHOP HERE

Men's & Women's  SHOP HERE

Men's & Women's  SHOP HERE

Men's & Women's SHOP HERE
Use RTR code RTRTOP4 for 5% off all products, even sale products

Men's & Women's  SHOP HERE

Men's & Women's SHOP HERE
FREE Shipping on most orders over $40

Men's & Women's SHOP HERE

Men's & Women's SHOP HERE

Men's and Women's SHOP HERE


Find all RoadTrailRun reviews at our index page HERE 
Google "roadtrailrun Shoe Name" and you can be quite sure to find just about any run shoe over the last 10 years

Enjoyed this post? Never miss out on future posts by Following RoadTrailRun News Feed

Please Like and Follow RoadTrailRun
Facebook:  Instagram: @roadtrailrun
Twitter: @RoadTrailRun You Tube: @RoadTrailRun

No comments: