Rab Mythic Ultra 120
Summary
Price At Time Of Writing | $864.95
Our Overall Rating | 90 out of 100
Pros - Lightweight, warm
Cons - Less versatile, mummy shape, half-length zipper
Overall - A sleeping bag for weight-conscious adventurers
Technical Specifications
Packed Size - 32x16cm
Weight - 330g
Fill - 900-Fill Power European Goose Down
Our Analysis & Ratings
The Rab Mythic Ultra 120 is a super lightweight sleeping bag made for people who need to keep their gear as light as possible without giving up warmth. Weighing just 330g, it packs in some impressive tech and top-quality materials to keep you warm while taking up barely any space in your bag. It's made with serious adventures like thru-hikes, bikepacking and mountain missions in mind, and while it won’t suit the average camper, it’s a smart option for those who need something compact, warm and simple.
Comfort - For such a light bag, the Mythic Ultra 120 is surprisingly warm and soft. The 900-fill duck down makes it feel fluffy inside, while the nylon lining is smooth and breathable. The narrow mummy shape helps trap heat and the shaped footbox has just enough wiggle room to stop your feet from feeling cramped. It’s snug, so if you move around a lot at night, it may take some getting used to. The hood covers your head nicely, but pairing it with a bigger pillow can feel a little awkward because of the tight space. Overall, it’s cosy for how small and light it is.
Construction - The outside is a super light ripstop nylon and the inside is made from recycled fabric with TILT, a shiny lining that reflects heat back at you. The down is treated with a water-repellent finish from Nikwax, so it still works if a bit of moisture gets in. There are loops underneath so you can attach it to a pad and stop it sliding around at night. Even when we used it straight on rocky ground, there were no signs of damage or down escaping. It’s clearly built with care, even if it feels delicate.
Features - This bag keeps things simple but smart. The main highlight is the heat-reflecting TILT lining that adds warmth without weight. There’s a half-length zipper that has a small flap to keep cold air out, and anti-snag tape to stop it from catching. The draft collar and hood help hold in heat. We do wish the zip went a bit further down for better airflow, but the shorter design helps keep weight down. It also comes with a small stuff sack and a mesh bag for storage. The pad loops are a nice extra for those who want to stay put at night.
Size/Weight - The Mythic Ultra 120 is one of the lightest down bags out there at just 330g. It packs down tiny, even smaller than the listed size, and ends up about the size of a large grapefruit. It comes in regular and long versions, so even taller people (up to 6’6"/198cm) can get a good fit. The regular size kept us warm on early summer trips with just a basic sleeping pad. Ultralight hikers will love how compact it is, but those used to roomier bags might find it too tight.
Versatility - This bag works best for lightweight trips during summer and the edges of spring and autumn. Rab says it’s comfy down to 0°C when used with a decent pad, and we found that pretty accurate. Thanks to the reflective lining and quality down, it feels warmer than you’d expect for its size. It’s not built for freezing winter nights or bulky layering inside the bag. The straps underneath help it work with different sleeping pads, but outside of that, it’s meant for specific conditions. People wanting a one-bag-for-everything setup will want to look at other options.
Overall - The Rab Mythic Ultra 120 is made for hikers, climbers and bikers who want a warm night’s sleep without carrying any extra weight. The mix of high-end down, smart heat-trapping fabric and lightweight build makes it a go-to for serious trips where every gram counts. The snug fit and short zip won’t work for everyone, but if you travel light and fast and care more about performance than extras, this bag delivers in a big way.
