Introduction

Brief Overview

The Rab Mythic Ultra 120 is a high-performance sleeping bag designed for serious outdoor enthusiasts who demand lightweight gear without compromising on warmth and comfort. Crafted with cutting-edge materials and innovative technologies, this sleeping bag is tailored for extreme conditions, making it an ideal companion for alpine climbers, mountaineers, and dedicated backpackers. With its ultra-lightweight construction, the Mythic Ultra 120 aims to provide maximum warmth while minimizing bulk, ensuring a restful night’s sleep even in harsh environments.

Initial Impressions and Context of Testing

Upon unboxing the Rab Mythic Ultra 120, the first thing that strikes you is its impressively light weight and compact size. Weighing in at just over 400 grams, this sleeping bag feels almost featherlight, yet it promises to deliver exceptional warmth thanks to its advanced insulation technology. The sleek design and high-quality materials immediately suggest that this is a premium piece of gear.

To thoroughly test the Rab Mythic Ultra 120, we took it on a multi-day alpine climbing expedition in the Rocky Mountains. This challenging environment, with its unpredictable weather and cold nights, provided the perfect testing ground to assess the sleeping bag’s performance. We encountered temperatures ranging from mildly cool to below freezing, allowing us to evaluate its insulating capabilities and overall comfort in varied conditions.

Technical Specifications

Key Features and Technology

The Rab Mythic Ultra 120 incorporates several cutting-edge technologies and features designed to enhance performance in extreme conditions:

• Thermo Ionic Lining Technology (TILT): This innovative lining uses a titanium coating to reflect body heat back towards the user, significantly improving thermal efficiency without adding weight.
• 900 Fill Power European Goose Down: Utilizes high-quality down with a fill power of 900, providing exceptional warmth-to-weight ratio. The down is ethically sourced and treated with a hydrophobic finish to maintain loft and insulation even in damp conditions.
• Ultra-lightweight Construction: Weighing only 400 grams, the Mythic Ultra 120 is one of the lightest sleeping bags in its class, making it ideal for weight-conscious adventurers.

Design and Materials

The Rab Mythic Ultra 120 is meticulously designed with premium materials to ensure durability, comfort, and performance:

• Outer Fabric: The outer shell is made from ultra-light 7-denier ripstop nylon, which is both robust and resistant to tearing.
• Inner Fabric: The inner lining is composed of a soft and breathable 10-denier nylon, providing a comfortable feel against the skin.
• Baffle Construction: Box-wall baffle construction ensures that the down remains evenly distributed, eliminating cold spots and enhancing thermal efficiency.

Additional Features

• Half-length YKK Zipper: A half-length zipper with an insulated baffle minimizes heat loss and reduces weight.
• Compression Sack: Includes a lightweight compression sack, allowing the sleeping bag to be packed down to an incredibly compact size, making it easy to carry in any pack.
• Anti-snag Zipper Tape: Prevents the zipper from catching on the fabric, ensuring smooth operation.

Performance Ratings

• Temperature Ratings: Comfort rating of -2°C (28°F) and a lower limit of -8°C (18°F), making it suitable for three-season use and mild winter conditions.
• EN13537 Certification: Certified to meet the European standard for sleeping bag temperature ratings, providing assurance of its insulating performance.

By integrating advanced materials and technologies, the Rab Mythic Ultra 120 offers a combination of lightweight design, exceptional warmth, and packability, making it an excellent choice for demanding outdoor adventures.

Performance Evaluation

Fabric Performance

• Breathability: The Rab Mythic Ultra 120 excels in breathability, thanks to its 10-denier nylon inner lining. This material effectively wicks away moisture, preventing the buildup of condensation inside the sleeping bag. During testing, even after a strenuous day of hiking, the bag remained dry and comfortable, reducing the risk of clamminess and ensuring a restful sleep.
• Waterproofing: While the Mythic Ultra 120 is not fully waterproof, it features a durable water repellent (DWR) coating on the outer shell. This treatment effectively repels light rain and moisture, keeping the down insulation dry. In misty and damp conditions, the sleeping bag maintained its loft and insulating properties without any noticeable decrease in performance.
• Durability: The combination of 7-denier ripstop nylon for the outer shell and robust stitching ensures the sleeping bag can withstand the rigors of outdoor use. Despite its lightweight design, it proved resistant to abrasions and tears during the multi-day alpine expedition, maintaining its integrity even when used directly on rocky ground.

Weather Resistance

• Cold Weather: The Thermo Ionic Lining Technology (TILT) significantly enhances the Mythic Ultra 120’s performance in cold conditions. By reflecting body heat back to the user, it ensures warmth even in temperatures as low as -8°C (18°F). On freezing nights, the sleeping bag provided consistent and reliable insulation, keeping us warm throughout the night.
• Wind Resistance: The tightly woven outer fabric offers excellent wind resistance. Even in gusty conditions, the Mythic Ultra 120 prevented cold drafts from penetrating, maintaining a cozy interior environment.
• Versatility: Suitable for three-season use, the sleeping bag adapts well to varying weather conditions. Its lightweight nature makes it ideal for summer use, while the advanced insulation ensures comfort in cooler autumn and mild winter nights.

Practical Features

• Zipper: The half-length YKK zipper, combined with an insulated baffle, minimizes heat loss and operates smoothly without snagging. The zipper’s placement also makes it easy to enter and exit the sleeping bag, even in cramped tent spaces.
• Baffle Construction: The box-wall baffle design ensures even distribution of down, eliminating cold spots and enhancing thermal efficiency. This construction also aids in maintaining the loft of the down, ensuring long-term performance.
• Compression and Packability: One of the standout features of the Mythic Ultra 120 is its exceptional packability. The included compression sack allows the sleeping bag to be compressed into a remarkably small size, making it easy to fit into any backpack. Despite its compact packed size, the sleeping bag quickly lofts back up when unpacked, ready to provide warmth and comfort.

The Rab Mythic Ultra 120’s performance in diverse conditions, combined with its practical features, makes it a top choice for outdoor enthusiasts seeking a reliable, lightweight, and highly functional sleeping bag.

Fit and Comfort

Sizing and Fit

The Rab Mythic Ultra 120 is designed to accommodate a range of body types while providing a snug fit essential for thermal efficiency. Available in regular and long sizes, the sleeping bag offers options for users of different heights. The regular size is suitable for users up to 6 feet tall, while the long size can comfortably fit individuals up to 6 feet 6 inches.

• Shape: The bag features a tapered mummy shape that contours to the body, reducing dead space and enhancing heat retention. This shape is optimized to balance warmth and weight, ensuring that every ounce contributes to thermal efficiency.
• Footbox: The footbox is anatomically shaped, providing extra room for your feet without compromising insulation. This design allows for natural foot movement and prevents the cramped feeling that some mummy bags can create.

Comfort During Various Activities

• Sleeping Positions: The Rab Mythic Ultra 120 caters well to various sleeping positions. Whether you sleep on your back, side, or stomach, the bag’s ergonomic design accommodates these positions without causing discomfort. The slightly wider shoulder area and tapered lower section offer a comfortable yet snug fit.
• Temperature Regulation: Thanks to its advanced Thermo Ionic Lining Technology (TILT) and high-quality down insulation, the Mythic Ultra 120 excels in temperature regulation. On warmer nights, the breathability of the materials ensures you don’t overheat, while in colder conditions, the sleeping bag retains body heat effectively.
• Hood Design: The snug, adjustable hood plays a crucial role in maintaining comfort and warmth. The hood is designed to envelop your head without restricting movement, and the drawcords allow for easy adjustments to create a customized fit that seals in warmth.
• Collar and Draft Tube: The inclusion of a well-padded collar and an insulated draft tube along the zipper further enhances comfort by preventing heat loss and keeping out cold drafts. These features are particularly appreciated during windy or freezing conditions.

Practical Features Enhancing Comfort

• Ease of Use: The half-length YKK zipper is strategically placed for easy access, allowing you to get in and out of the sleeping bag without hassle. The anti-snag tape ensures smooth operation, adding to the overall convenience.
• Interior Space: Despite its mummy shape, the Rab Mythic Ultra 120 provides ample interior space for a comfortable sleep. The slight roominess around the shoulders and feet ensures that you don’t feel constricted, which is a common issue with many mummy-style sleeping bags.
• Material Feel: The 10-denier nylon inner lining is soft to the touch, providing a comfortable surface against your skin. This material also aids in moisture management, wicking away sweat and keeping you dry throughout the night.

The Rab Mythic Ultra 120 combines a well-thought-out design with high-quality materials to ensure maximum comfort and a tailored fit for various body types and sleeping positions. Whether you’re spending a night in a tent high in the mountains or camping in milder conditions, this sleeping bag promises a restful and cozy sleep.

Pros and Cons

Advantages

• Ultra-lightweight Design: Weighing just over 400 grams, the Rab Mythic Ultra 120 is incredibly lightweight, making it an excellent choice for weight-conscious hikers and climbers.
• Exceptional Warmth: The use of 900 fill power European goose down and Thermo Ionic Lining Technology (TILT) ensures excellent insulation, keeping you warm in temperatures as low as -8°C (18°F).
• Compact Packability: The included compression sack allows the sleeping bag to be packed down to a very small size, optimizing space in your backpack.
• Durability: Constructed with 7-denier ripstop nylon for the outer shell and robust stitching, the Mythic Ultra 120 is designed to withstand the rigors of outdoor use.
• Comfortable Fit: The ergonomic mummy shape, spacious footbox, and adjustable hood provide a comfortable and snug fit, enhancing overall sleep quality.
• Breathability: The 10-denier nylon inner lining effectively manages moisture, preventing clamminess and maintaining a dry interior.
• Wind and Weather Resistance: The tightly woven outer fabric and DWR coating offer good resistance to wind and light moisture, ensuring performance in varied conditions.

Drawbacks

• Price: The advanced technology and high-quality materials used in the Rab Mythic Ultra 120 come at a premium price point, which might be a barrier for some users.
• Limited Zipper Length: The half-length zipper, while reducing weight, can make entry and exit slightly more challenging compared to full-length zippers.
• Seasonal Limitation: While it excels in three-season use and mild winter conditions, the Mythic Ultra 120 may not provide sufficient warmth for extreme winter expeditions below its rated temperature.
• Color Options: The sleeping bag is available in limited color options, which may not appeal to users looking for more variety or visibility in their gear.
• Specialized Use: The ultralight and specialized design might not be necessary for casual campers or those who do not prioritize weight savings.

The Rab Mythic Ultra 120 stands out for its exceptional warmth-to-weight ratio, durability, and comfort, making it an excellent choice for serious adventurers. However, its premium price and specific design features may not be suitable for everyone.

Comparative Analysis

Rab Mythic Ultra 120 vs. Feathered Friends Swallow UL 20

The Rab Mythic Ultra 120 and the Feathered Friends Swallow UL 20 are both high-performance sleeping bags designed for serious outdoor enthusiasts. The Rab Mythic Ultra 120 excels in its ultra-lightweight design, weighing just over 400 grams, making it one of the lightest options available. It uses advanced Thermo Ionic Lining Technology (TILT) and 900 fill power goose down to provide exceptional warmth down to -8°C (18°F). In contrast, the Feathered Friends Swallow UL 20, while slightly heavier at around 680 grams, offers a wider temperature range with a comfort rating of -6°C (20°F). Both sleeping bags feature high-quality down insulation and durable materials, but the Swallow UL 20 offers a full-length zipper for easier access and slightly more interior space, making it a bit more versatile for varying conditions.

Rab Mythic Ultra 120 vs. Kelty Cosmic Down 20

Comparing the Rab Mythic Ultra 120 to the Kelty Cosmic Down 20 highlights differences in both performance and pricing. The Mythic Ultra 120, with its advanced technologies and high fill power down, comes with a premium price tag, justified by its ultra-lightweight and high warmth-to-weight ratio. The Kelty Cosmic Down 20, on the other hand, is a more budget-friendly option, offering decent performance with 550 fill power down and a comfort rating of -7°C (20°F). While it is heavier and bulkier compared to the Mythic Ultra 120, the Cosmic Down 20 is an excellent choice for those seeking reliable performance without the higher cost. It features durable materials and a full-length zipper, making it a versatile and accessible option for three-season camping, though it may not provide the same level of warmth or packability as the Rab Mythic Ultra 120.

In summary, the Rab Mythic Ultra 120 stands out for its ultra-lightweight design and high-performance insulation, making it ideal for serious adventurers who prioritize weight and warmth. The Feathered Friends Swallow UL 20 offers slightly more versatility and ease of use with its full-length zipper, while the Kelty Cosmic Down 20 provides a more affordable alternative with reliable performance for a broader audience.

Verdict

The Rab Mythic Ultra 120 is an exceptional sleeping bag designed for serious adventurers who prioritize lightweight gear without compromising on warmth and performance. Its combination of advanced Thermo Ionic Lining Technology (TILT), high-quality 900 fill power goose down, and ultra-lightweight construction makes it a standout choice for alpine climbers, mountaineers, and dedicated backpackers. Despite its premium price, the Mythic Ultra 120 offers excellent value for those who demand the best in terms of weight savings and thermal efficiency. It excels in cold weather conditions, packs down to an impressively compact size, and provides a comfortable fit for various sleeping positions. However, its specialized design may not be necessary for casual campers or those on a tighter budget. Overall, the Rab Mythic Ultra 120 is highly recommended for outdoor enthusiasts seeking a top-tier sleeping bag for extreme and lightweight adventures.