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Reviews > Clothing > Hats, Caps and Visors > Chaos Adrenaline Combo Skully > Test Report by Derek Hansen

Chaos Skully Cap

Photo courtesy

Adrenaline Skully Cap

Test Series by Derek Hansen



NameDerek Hansen
Height5' 10" (1.78 m)
Weight165 lb (75 kg)
Head Size23 in (58 cm)
Email Address Obfuscated electronic contact information
City, State, CountryFlagstaff, Arizona, USA


I am a lightweight backpacker with a typical weekend pack weight of 15 lb (7 kg) and a multi-day weight of 20 lb (9 kg), which includes food and water. I prefer lightweight trail-running shoes and backpacking with a hammock as part of my sleep system.


Manufacturer Chaos (Steamboat Springs, Colorado, USA)
Year of Manufacture 2011, made in China
Manufacturer’s Website
MSRP US$14.99
Listed Sizes Jr., Adult
Size Tested Adult
Color Black
Listed Weight N/A
Measured Weight 1.25 oz (35 g)
Listed Features

"Ultra-Light Liner Skully Drirelease Provides Superior warmth and wicking compared to other fabrics ideal for layering under a helmet or wear alone"


"You can return most new, unopened items within 30 days of delivery for a full refund. Unless otherwise noted, the refund will be for the full value of the returned items. Shipping and handling fees will not be refunded. "

Care and Use Machine wash cold, gentle cycle. Do not bleach, do not wring out. Dry flat.


14 Feb 2011


Skully, front view

The Chaos Thermal Regulation (CTR) Adrenaline Combo Skully, or just “Skully” came packaged with four hang tags to describe the different fabric technologies used in the product. The Skully is a fitted head cap that looks similar to a swimmers cap when worn — it fits tightly around my head, ears, and upper neck. The cap is constructed out of 83% Polyester, 11% wool, and 6% Spandex. There is a care tag sewn into the back seam of the cap and a “CTR” logo printed off-center in the front.

Skully, back view

The cap is sewn with flat-lock seams. The top portion of the cap is made with PRO-STRETCH, form-fitting, 4-way stretch, moisture wicking, highly-breathable polyester and Spandex fabric. The lower portion of the Skully (the fabric that surrounds the ears, upper neck, and brow, is made from two layers of the drirelease wool performance fabric.

The hang tags also indicate that the drirelease fabric dries four times faster than cotton (and according to a pie chart, drying faster than Coolmax, Coolmax Alta, Hydrotec, and nylon) and contains FreshGuard to manage odor.

Chaos lists the Skully as “ideal for under helmet or wear alone.” The drirelease wool is listed as having no static cling, ideal as a base layer, and “wool warmth without the weight or itch.”


The Skully is indeed light, although the manufacturer lists no weight. I am also intrigued by the construction of the cap — for example, the dual-layer wool fabric being only around my ears and neck and not everywhere. The PRO-STRETCH fabric is listed as “highly breathable”, which is all the material on the top of my head. I will really try and see how heat is retained on the top of my head and if I will need to use a second cap for really cold temperatures.

The cap feels smooth and stretches enough to easily cover my head without feeling too tight. When pulled down over my ears, I can still hear well; there is not a lot of muffling.

PRO—Light, smooth feel, good fit without too much tension.

CON—None yet.


26 April 2011


I have used the Skully dozens of times during the past few months including multiple bicycle rides, trail runs, a few day and snowshoeing hikes, and three overnight backpacking trips. Here are some highlighted trips:

Feb 19Old Caves Crater, Flagstaff, Arizona. About 3 mi (5 km), elevation 7000 ft (2100 m). Blizzard conditions with wet snow. Temperature in the 30s F (~0 C).

Mar 4-5West Fork of Oak Creek, near Sedona, Arizona. About a 6 mi (10 km) hike with an elevation of about 5000 ft (1500 m). Snow and ice along the trail and high, cold water in the river. The temperatures were in the upper 40s F (5 C).

Mar 11-12Wet Beaver Creek, near Camp Verde, Arizona. Overnight camping trip with the Boy Scouts. We camped at an elevation of 3800 ft (1160 m) and did a few day hikes, including ascending a small mesa at 4120 ft (1256 m). We hiked about 2.5 mi (4 km) total. Temperatures during the day were in the upper 60s F (16 C) and low 40s F (4 C) at night.

15 MarGrand Falls, Arizona. A 2-mile (3 km) day hike with the family to Grand Falls on the Little Colorado River at an elevation of 4800 ft (1463 m). Lots of water and mist with temperatures in the 60s F (~15 C).

Mar 18Mount Humphreys, Kachina Trail, Flagstaff, Arizona. About 3 mi (5 km), elevation 10,000 ft (3050 m). Deep snow and varying conditions. Temperature in the upper 50s F (10 C).

16 AprOldham Trail, Arizona. Mountain biking with friends in the foothills of Flagstaff. A short 5-mile (8 km) trip with some new riders, including myself. Temperatures in the 60s F (~15 C).

Apr 22-23Snow Canyon Overlook, Utah. I led a group of my children, nieces, nephews, brother, and cousin on a backpacking trip on the Red Mountain Trail to the Snow Canyon Overlook in southern Utah. 4.6 miles (7.4 km) of hiking. Elevation is 5000 ft (1524 m). Temperatures were in the high 30s, low 40s F (~0-4 C) at night with a light sprinkling of rain.



Mountain biking on Oldham Trail

A bit too much cheek. I had just removed my helmet to adjust my camera, which is why I look extra silly in this photo. The Skully works great under a helmet, even if the wearer is a ham.

The Skully is great to wear under helmets and other hats. During several bicycle commutes and rides, I've used the Skully under my helmet and I haven't had to adjust my straps to accommodate any extra bulk. There are no pressure points; the Skully has stretched to fit my head and has retained its elasticity. On a few snowshoeing trips, I've worn the Skully and found that it easily fits under without needing adjust my wide-brimmed hat.

Even with a helmet or hat on, I do not feel the flatlock seams. I've been able to wear the Skully for hours while hiking without any problems due to fit or pressure.

I should probably mention that my hair is cut short and tight, so not a lot of bulk underneath.



Here, I've taken off my wide-brimmed hat to reveal the Skully underneath.

This is one area where I've had mixed feelings. The Skully has different material on top and around the ears and brim. The top is highly breathable. The brim has the wool, which is nice and warm and adds a bit of wind resistance to the hat. On lower impact hikes in the cold, I've found that the Skully alone isn't enough to keep the top of my head warm, although my ears are fine. I've added a warmer fleece hat when sleeping or hiking, or even a wide-brimmed hat over the Skully to cut the wind and add warmth on top. Just cutting the wind is enough in some cases. The top really breathes well (did I mention that already?)

Trail running

On a trail run up Schultz Pass in Flagstaff, Arizona.

On my morning trail runs, I've worn the Skully alone, which has been perfect. For high-impact running or climbing/hiking, the Skully's breathable top has been great. The heat and moisture releases well and I haven't felt overly hot. The added warmth around my ears has worked great.

In a nutshell, the Skully works best for high-impact activity. For low-impact, with cold weather, I've had to have additional layers to keep my head warm.


I hand washed the Skully once this period using Dr. Bronners organic soap. I let the hat air dry. The Skully dries quickly and has retained its color, shape, and elasticity.


On my trip into Oak Creek with my daughter, I thought I packed the Skully but couldn't find it during the trek. I looked everywhere for the hat but had to start hiking to beat the sunset. Later, when I dumped out my backpack, I found the Skully hidden in the bottom of my pack. I learned to keep the Skully in a side pocket for easy recovery. This hat packs so small and is so light it is easy to lose (the dark color made it especially impossible to find at night).


I've used the Skully to sleep in my hammock during my overnight backpacking trips. On my most recent trip in April to Snow Canyon, the low temperature was in the high 30s (0-2 C), which was perfect for the Skully alone. I didn't have any cold spots on my head all night. In colder temperatures, I've had to add another layer to stay warm.


PRO—Very breathable on top. Warm around ears. Fits great under hats, helmets. No tight spots.

CON—Not as warm on top.

Please check back in approximately 2 months (June, 2011) for my long-term report.


23 June 2011


I've taken the Skully on about six additional day hikes and two overnight camping trips. Here are three highlighted trips:

14 MayFlagstaff, Arizona. I took the Boy Scouts on a 12-mile shakedown day hike up and around Mount Elden in Flagstaff. The trek started at 6 AM to ascend the 2300 ft (700 m) elevation change—base elevation at 6900 ft (2100 m), and topping out at 9200 ft (2800 m). The temperatures in the morning were a brisk 35 F (2 C) and topped off to a dry 70s F (~20 C).

3-7 JunVarious locations, Utah. While returning from bereavement leave, my family and I went on several day hikes in the mountains of northern Utah, and Capitol Reef National Park, while taking in the sights at Grand Staircase/Escalante, and Bryce Canyon.

20-21 JunWest Fork of Oak Creek, Arizona. I took relatives along the 6 miles (10 km) of trail and slept in hammocks. Temperatures were in the 80s F (~30 C) during the day and 40s F (~5 C) at night.


The Skully has worked great and been an easy pack item on all my hikes and trips during this testing phase. While doing our long day hike around Mount Elden, I was one of the only ones in our group with a few extra layers to stave off the cold and wind we encountered on the all-but-bald east face. I wore the Skully under my sun hat, which worked well. The Skully cap kept me warm while also wicking moisture and breathing well enough that I never overheated, even though it was a strenuous climb.

In Oak Creek, I wore the Skully as a sleep cap in my hammock and the cap provided enough warmth to keep me feeling toasty on top.

At the highline ridge on Mount Elden


I am very pleased with the Skully cap overall. I love how small and light it is and the varying warmth it provides, especially when exercising. For moderate temperatures, the hat works well alone, and it really works well with other layers.

This is one piece of gear I plan to keep in my packing list.

PRO—Easy and light to pack. Comfortable.


Read more gear reviews by Derek Hansen

Reviews > Clothing > Hats, Caps and Visors > Chaos Adrenaline Combo Skully > Test Report by Derek Hansen

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