Skip to content →

Review of the Osprey Momentum 34 Backpack

This is a review of the Osprey Momentum 34 backpack, which is pitched as Osprey’s bike commuter backpack. It can be had on for around $150 USD.

This review discusses the features of the bag that make it great. This review also compares it to the following bags which I also own.

Before I begin the review, I’ll just give a bit of background about my requirements for a commuter bag. I commute to work by bike each day. My trip is about 12 miles each way. I carry a separate set of clothes, my 13″ Macbook Air, and some other odds and ends.

I need a commuter bag to obviously carry all of this stuff, but also I need it to be comfortable, durable, and lightweight.

Design and features

The Momentum 34 is designed specifically for bike commuters, and its features make that obvious.

  • Dedicated, padded laptop pocket
  • Helmet leash (attaches a helmet to the outside of the bag)
  • On-shoulder pockets
  • Large main compartment
  • Compression straps
  • Reflective markings
  • Waterproof rain fly
  • Additional “briefcase” style carry handle
  • Pockets to hide waist belts and shoulder straps
  • Dedicated U-lock pocket
  • Comes in two sizes: S/M, and M/L (this review is of the M/L)

The bag is pretty aesthetically appealing. It comes in a very dark gray or bright yellow.

Image of Osprey Momentum 34 Bag

A very accessible front pocket with decent organization will fit a small notebook, some pens, and other odds and ends.

There is a cavernous main pocket that easily fits a large volume of stuff. It also has a bit of mesh organization and an inner zippered mesh pocket. The zipper for this pocket can be tough to open, especially if the zipper handle lands below one of the compression straps.

The laptop pocket has a lot of really good padding. It fits a 13-inch Macbook Air with tons of room to spare. I think that this pocket would easily fit a 17-inch laptop. The only thing missing is a bit of padding on the bottom of the bag to protect the laptop from falls. The rain fly provides a bit of padding, but there’s no dedicated foam on the bottom.

The U-lock pocket is super convenient, and is a great idea for a bike commuter bag. Think about it, the first thing that any bike commuter reaches for after arriving is their U-lock. The fact that this pocket is on the outside of the bag and so accessible is a huge plus. The pocket fits my Kryptonite Evo Mini-7 with 4-foot Flex Lock, and there is still room to spare.

There are also some pretty large side pockets that zip shut. When unzipped, some elastic and mesh webbing allow these pockets to hold a 1-liter water bottle without it falling out. I put my bike tools in these pockets, keeping them out of the way of the stuff I access regularly.

The back of the bag is a washboard foam, that acts a bit like a pack frame. It’s pretty sturdy, and fits the contour of my back pretty well. My back gets a bit sweaty from carrying this pack, because the foam will sit right against your back. Not much can be done about this. Osprey has a better design on some of their other packs, called the AirScape, but I suspect that that design wouldn’t be effective for bike commuters. When riding your bike, you’re leaned forward (at least on a road bike), and therefore the pack will lay itself against your back anyway.

I’m not concerned about getting sweaty, as my commute is already long enough to cause me to sweat, but for some people this might be a small issue. I’ve noticed that my back barely sweats while wearing this pack around casually.

The two shoulder-strap pockets are pretty awesome. The right one has a retractable key leash. That might be the part of this bag that will actually wear out. However, the key leash is replaceable, as it’s just clipped on to a loop inside the pocket. The key leash isn’t proprietary, it’s just some standard thing with an Osprey logo. You could easily replace this with any $0.50 thing you find in a hardware store.

The left pocket is meant for a cell phone or other small items. Since I commute to work with a Garmin Edge 500 on my bike, there’s no reason for me to keep my phone accessible (e.g. if I were using the My Tracks or Strava Android apps). Since I don’t need to keep my cell phone up there, I instead put my wallet and Google badge there, as I need those things more frequently. However, if you’re wondering, the Samsung Galaxy Nexus barely fits in that pocket. The Samsung Galaxy Nexus is easily the largest but thinnest phone I’ve ever owned, so you can consider that an upper bound for size.

The shoulder straps can be tucked away if you don’t need them. This isn’t a feature I’ll ever use, but I could see it being useful if someone wanting to convert this to more of a briefcase style bag while walking around. The bag even has a handle on the side that allows it to be carried like a briefcase. When not in use, that handle isn’t noticeable or in the way.

Osprey paid a lot of attention to making sure that straps on this bag were adjustable and comfortable. The waist strap is no exception. It’s long enough for it to fit on a pretty big person, and really stabilizes the bag. If you don’t want to use it though, there are pockets allowing it to be tucked away so that it’s not dangling when not in use. This is a great feature, in my opinion, because too often, technical backpacks have straps hanging everywhere and they get caught on stuff all the time.

The rain fly that comes with the bag is super convenient if you get caught in the rain. A lot of thought was even put into the design of the rain fly. It’s made out of a waterproof material that is super bright yellow. It buckles across the back of the bag, and lashes tight to ensure that no wind or water pull it off. It comes in a dedicated pocket on the bottom of the bag, and is removed completely by detaching its velcro from inside the pocket. The rain fly also has some reflective markings on the back and a light attachment. Cars will have no trouble seeing you while wearing this on the outside of the bag.

Packing the bag

Every day when commuting, I carry the same 9.8 pounds of stuff (with the Momentum 34, that totals to 12.8).

Image of everything that I pack in the bag

And it all fits in the Momentum 34 beautifully. I was surprised at how small of a package it made in this bag, because in other bags it seemed like so much stuff. Here are some photos of the bag filled with everything shown.


Even with all of that stuff, the bag feels balanced, secure, and comfortable. It’s noticeably more comfortable than all of my other bags. A smile came to my face when I tried it on loaded. It’s really great at carrying everything a commuter would need.

I’m 6’4″ tall, and the M/L size fits me perfectly. The back of the pack fits my back very well, and I’ve found it super comfortable.

The shoulder strap padding could probably be a little bit longer, just so the “fat” part of the strap occupied more of my chest, but it’s really a non-issue.

Durability and warranty

The Momentum 34 seems tough. It doesn’t quite seem “bomb proof” (as some messenger bag companies have come to call the material of their bags), but it seems like it will take a beating. All of the zippers, stitches and buckles seem very formidable. I haven’t yet encountered a stuck zipper or loose stitch. I haven’t hurt the bag in any way yet, but am looking forward to it!

When I do hurt the bag, I won’t have to worry. Osprey provides something called the All Mighty Guarantee, which is essentially a lifetime guarantee to repair ANY damage or defect in the bag, for free. That includes damage to the bag that is not Osprey’s fault! This is quite an amazing warranty, and it’s pretty much the first of its kind I’ve encountered. Hats off to Osprey for really standing up for their products, this really makes the Momentum 34 a “buy it for life” product.

Compared to the Osprey Momentum 26

In buying this bag, the biggest question in my mind was whether to get the 26-liter or 34-liter version. What I decided to do instead was order both, and take advantage of Amazon’s free returns policy on bags.

There are a few notable differences between the 26-liter and 34-liter versions.

  • 26-liter does not have an external U-lock pocket, they moved it inside.
  • Side pockets of 26-liter do not zip shut.
  • Main pocket is somewhat smaller.
  • 34-liter version felt more comfortable on my back.

Despite these differences, the bags look and feel identical. They appear to be almost exactly the same size when compressed. It’s hard to tell, but in the first image below, that is actually the 26-liter version in front of the 34-liter version. Notice how you cannot even see the 34-liter version behind it. I could not tell the difference in weight while holding both in each hand. For these reasons, and the differences noted above, I highly recommend going with the 34-liter version if you’re on the edge.

Compared to the Chrome Citizen

The Chrome Citizen is a completely different bag than the Osprey Momentum 34, but they are intended to serve similar purposes. Mainly, people on bikes need to carry their stuff in a bag. I thought for a long time that I personally preferred a messenger style bag like the Citizen. However, over time, I’ve grown to dislike it.

The Citizen has a lot of fashion/style going for it. Other than that, though, I actually think it’s not an ideal bag unless you’re actually a bike messenger. I’ve traveled around the world with nothing but the Chrome Citizen, and have ridden hundreds of miles with it on my back. Still, its design flaws get to you after a while.

  • When loaded up, the Citizen eventually hurts my left shoulder (after more than 30 minutes of wearing it).
  • Again, when loaded up, it eventually gets annoying for me to breathe, because the Citizen pulls on my chest.
  • The laptop sleeve of the Citizen attaches to the outer side of the bag, not the side closest to your back. This means that everything you put next to your back gets felt on your back. A pair of shoes, for instances, will dig into your back. This seems backwards to me. Anyway, if you want to use a laptop sleeve with the Chrome Citizen, it can only be attached to one side.
  • The Citizen doesn’t have any built-in shoulder strap pockets. You can buy one as an accessory that attached to the strap, but really small things (keys) can fall out of it.
  • It’s a pain in the ass to take on and off. The seatbelt strap is actually seatbelt material. So it flops all over the place when not attached. Sometimes I hit things with it while pulling it up to buckle it.
  • The buckle of my Citizen has started to rust a bit.
  • To access anything, you have to flip the bag around, unbuckle two buckles, undo the huge velcro flap, and then dig around in the single main pocket or the small front pockets. Every time you need something you have to do this. It’s annoying from day one.
  • It’s one huge 26-liter pocket, and I found this to be barely enough for all of my stuff.
  • It does not distribute load down your back well, and eventually it’s a little rough carrying ~10 pounds of stuff in it. In airports, while carrying a week’s worth of gear, I sometimes just carry it on my right shoulder instead of across my chest because it’s more comfortable, although less secure.
  • After sweating on it a lot, it looks gross and needs to be washed. The outer fabric is basically cotton, so it absorbs all of the sweat, and eventually builds up white sweat stains.
  • Chrome’s website says it weighs 2.5 pounds, but I honestly think it feels heavier empty than the Momentum 34. I think the tarp liner and steel buckle add a lot of weight.

The Momentum 34 doesn’t have any of these drawbacks. That alone makes me love the Momentum 34.

Here are some photos showing the differences between the two bags.

Compared to the Crumpler Moderate Embarrassment

The Moderate Embarrassment is still my go to bag for commuting to work casually (e.g. without a bike). I’ve even taken it on some same-day roundtrip flights. It fits just my laptop, Kindle, and other few items very well. It’s small, light, and comfortable. It doesn’t hold all of the things that the Momentum 34 holds, but when I use it, it doesn’t need it to.

Again, here are some photos for comparison.

Compared to the Osprey Kestrel 32

The Osprey Kestrel 32 is more of a daytrip pack. It’s meant to be one huge pocket with compression straps, and a comfortable fit. The Kestrel actually has the AirScape design for the back, which is nice because it makes my back less sweaty while wearing the bag. Other than that, though, the Kestrel is purposed at backpacking, and not commuting. I’ll probably still use the Kestrel for daytrips, but otherwise I’ll be using the Momentum 34 for more general purpose carrying from now on. What surprised me was that the Kestrel 32 actually appears bigger than the Momentum 34, even though the Momentum 34 is technically two liters larger.

More photos for comparison.


The Momentum 34 is easily the best all-around bag I’ve bought to date. I love it. It’s comfortable and convenient, and has so many amazing features meant for bike commuting. I give it a solid 9/10 rating. The only things I’d like to see are the AirScape back (or some other suspension system for keeping your back cool), and more accessible zippers on the main pockets. I found the zippers a bit too “tough”, and sometimes it was a bit annoying to get access to the pockets.

If you’re looking for a commuter backpack, this is the one, hands down.

Published in Uncategorized