Pajak Radical 1Z Review

Overview

The Radical 1Z is the lightest full-length, hooded bag in Pajak’s Radical line, a Polish-made down mummy that weighs 440 g in Regular and packs to about 2.2 liters. It is built for spring and summer trips, tarp camps and bikepacking, where the goal is a sleeping system that nearly disappears in the pack. The trade-off is a rating that suits warm nights only, at a price that buys European construction more than extra warmth.

Key Specs

Spec	Detail
Weight	420–480 g depending on size (440 g Regular)
Fill	900 CUIN Polish goose down, RDS-certified, 95/5 blend
Fill weight	235 g (Pajak’s stated figure)
Comfort / limit / extreme	5°C / 0°C / −15°C (ISO 23537)
Packed volume	2.1–2.3 L (2.2 L Regular)
Construction	Angled Z-baffle, close-fitting mummy shape
Shell	Gelanots Ultra Light Ripstop polyamide, hydrophobic finish, PFAS-free water treatment
Zipper	YKK, left side, two-way, with insulated draft tube
Extras	Hood with one-handed adjustment, inner pocket, internal and external hang loops, storage/compression sack
Shoulder / foot width	82–84 cm / 50 cm
Made in	Europe

Performance

Warmth. The numbers set the expectations. A 5°C comfort rating under ISO 23537 puts the Radical 1Z firmly in warm-season territory, with a 0°C limit rating for those who sleep cold-tolerant. The −15°C extreme figure is a survival number, not a plan. Pajak’s own copy says the bag performs best around 5°C and goes lower with layered sleepwear, and retailers split on how to label it: some call it three-season, others two-season. Treat it as a summer and shoulder-season bag. Used from late spring through early autumn at moderate elevation, it fits that role. Hikers expecting frost should look at a warmer model.

Construction. Z-baffles, a close mummy cut and a draft tube along the zipper are meant to eliminate cold spots and keep the 900-fill down lofted. The bag also has 3D baffles at the zipper and collar. The 95/5 down comes from Poland, and a QR code on the product traces the origin of the down. European retailers describe the shell as water-repellent and breathable. That’s the usual story for a hydrophobic ripstop: it will handle condensation and tent-wall brushes, but it is not a substitute for a dry sleeping spot.

Packability. This is where the bag earns its price. At 2.2 L for the Regular, it disappears into the bottom of a small ultralight pack or a bikepacking seat bag. Owners on European retail sites consistently list low weight and easy compression as the main reasons to buy.

Comfort and fit. Despite the mummy shape, buyers regularly describe the bag as roomy for its weight class, with a 50 cm foot box and 82–84 cm at the shoulder. The full-length two-way zipper makes it easy to vent on warm nights, which is a real advantage in a bag used mostly above 5°C. The left-side zip is the only option; there is no right-zip version. The inner pocket holds a phone or headlamp.

Known weak spots. One owner of an earlier version of the bag called the hood adjuster a design flaw, saying the cord end kept tapping his face while he tried to sleep. The review dates to 2019, and the current hood is described as adjustable with one hand, but side sleepers who dislike dangling cords should check the cord before a trip. A zippered, non-locking slider also snags on thin shell fabric if it isn’t managed carefully, as it does on any ultralight bag.

Choosing a Version

The Radical 1Z comes in three lengths, all with the same temperature ratings and similar widths. Only length and the amount of down change.

• Short (M): fits users up to 165 cm and measures 185 cm long. It is the lightest and smallest of the three, at 420 g and about 2.1 L. It suits shorter hikers, and saves a few grams for those who fit it.
• Regular (L): fits users up to 180 cm, with a 200 cm length and the benchmark 440 g weight. This is the size most buyers will want.
• Long (XL): fits users up to 205 cm and measures 230 cm long. It carries more down and fabric and packs to about 2.3 L. Taller hikers should choose it rather than squeeze into the Regular, since a bag that is too short compresses the down at the feet and loses warmth.

Pros & Cons

Pros

• 440 g in Regular, with a 420 g Short available
• 2.2 L packed volume, compact enough for small packs and bikepacking bags
• Rated to ISO 23537, so the temperature figures are comparable with other certified bags
• Full-length two-way YKK zipper with a draft tube for venting on warm nights
• 900-fill, RDS-certified down with traceable origin
• Roomy for its weight class, with a hood, inner pocket and hang loops

Cons

• A 5°C comfort rating limits it to summer and mild shoulder seasons
• Street prices run roughly €400–430 at European retailers, a premium for a warm-weather bag
• Left-zip only
• Earlier versions drew complaints about the hood adjuster cord
• The shell has a water-repellent finish only, not a waterproof one

Who Should Buy This

Ultralight backpackers and bikepackers who sleep on nights that rarely drop below 5°C, and who want a proper hooded bag instead of a quilt, are the target. It also suits those who want European-made down gear and ISO-rated numbers. Cold sleepers, anyone planning alpine or early-spring trips with frost, and hikers who want a sleeping bag that doubles as a camp blanket should look at a warmer bag or a quilt with more fill.

Verdict

The Radical 1Z does what its name promises: a full hooded bag at a weight that rivals many quilts, packed into a 2.2 L stuff sack. It’s expensive for a bag rated to 5°C, and it doesn’t stretch into cold conditions. For summer thru-hikers and fast-and-light overnighters, it’s a well-made, strong choice.