COMFORT/FIT  
The Fjällräven Rucksack No. 21 provides decent overall comfort while carrying heavier loads in colder weather for distances shorter than six miles. 

While the Fjällräven Rucksack No. 21 does not offer a hip belt, its ergonomic shoulder straps contain enough padding to make them comfortable under heavier loads. The downside to the shoulder straps is that they cannot be adjusted on the fly. Wider shoulder widths (e.g. larger males) may find them too narrow. However our tester found them to be comfortable.

The back panel, which is made with two 2.5-wide strips of heavy closed-cell foam covered in canvas, runs vertically on both sides of the spine. The pack conformed to our tester’s back and made the pack comfortable in the cycling position even with a laptop inside. However the lack of breathability in the back panel during long distance rides in hot, humid weather will decrease comfort. 

STABILITY
The Fjällräven Rucksack No. 21 is a stable pack when riding a commuter bike and carrying a laptop. Despite the lack of a sternum strap, our tester found that the pack moved very little on her back. However, the pack itself is shorter in the torso and narrow in the shoulders and may not be a good fit for larger cyclists. 

STORAGE
The Fjällräven Rucksack No. 21 offers twenty liters of cargo capacity. The main compartment, which is accessed via a drawstring closure, offers a small secured zip pocket for valuables and a large, unpadded sleeve that can hold up to a seventeen-inch laptop, a medium-sized unpadded sleeve that can hold an eReader or tablet, and a drawstring pocket holds a thermos or waterbottle in the upright position. 

Outside the pack is a medium-sized pocket that is semi-secure when the top flap is buckled down; however, securing the snaps of the top flap are labor intensive, which makes impedes quick access. The only quick-access pockets available on the pack are two unsecured, non-stretch side pockets that are flush with pack. However, our tester found that the usefulness of these pockets are limited to carrying items that are flat and small, such as her bike lock, wallet and cellphone and overstuffing them decreases internal cargo space. 

DURABILITY
The Fjällräven Rucksack No. 21 is arguably the best-constructed pack in the test. Made with Fjällräven’s proprietary G-1000 fabric, which is a tight, densely-woven composition of sixty-five percent polyester and thirty-five percent organic cotton. It is then treated with Greenland Wax, making it extremely durable and resistant to water, weather, dirt, grit and general abrasion. However, the Greenland Wax coating will need to re-applied over time to maintain the water- and weather-resistance. 

EXTRAS
A padded seat pad is also included with the Fjällräven Rucksack No. 21 which, our tester found, works well as padding for her laptop and adds additional structure to the pack. However, the seat pad does occupy space at the rear of the pack and can interfere with access to the laptop compartment. 

Inside the pack is a drawstring pocket that holds a thermos or a water bottle in the upright position.