Hennessy Ultralite Asym Zip Hammock Hex Fly Review: Tested 3 Seasons

After spending three seasons testing the Hennessy Ultralite Asym Zip with Hex Fly on everything from weekend overnights to a week-long section hike, I can tell you exactly who this hammock is for.

The Hennessy Ultralite Asym Zip is an excellent choice for ultralight backpackers and thru-hikers who want a complete sleep system under 1.5 pounds. The asymmetrical design actually delivers flat sleeping comfort, the Hex Fly provides solid rain protection, and the bottom entry keeps bugs out effectively.

It's not for everyone though.

If you are over 6 feet 2 inches tall, want instant setup without practice, or camp primarily below 40 degrees, you might want to look elsewhere.

Let me break down exactly what you are getting into with this premium hammock system.

First Impressions: What's in the Package

When my Hennessy arrived, the first thing I noticed was how small the package was. The entire hammock system compresses to roughly the size of a grapefruit.

But opening the package revealed something important that was not there.

No tree straps.

This is a common complaint from first-time Hennessy buyers. The hammock comes with a suspension ridgeline, but you will need to budget another $20-40 for tree straps. After testing five different suspension systems, I recommend Dutchware 1-inch webbing straps with Dutch clips for simplicity and reliability.

The quality of materials was immediately apparent. The 40D ripstop nylon feels substantial yet lightweight, and the no-see-um mesh is fine enough to keep out the tiniest biting insects. The zipper operates smoothly, though I have noticed it can be sticky when the hammock is under tension.

Design and Features: The Hennessy Difference

Is the asymmetrical design actually better?

The bottom entry system is Hennessy's signature feature. Instead of flipping open a top flap, you enter through a zipper opening in the bottom of the hammock. You sit in first, then lift your legs and roll over into position. It sounds awkward.

It is awkward at first.

But after about 10 setups, I found I could enter faster than any top-entry hammock I have used. The real advantage is that bugs never get inside when you are entering or exiting. With a top entry, there is always that moment when mosquitoes swarm in.

The integrated mosquito netting is full-coverage and sits high enough that it does not press against your face. I have spent buggy nights in the Adirondacks where tent campers were getting eaten alive. I slept bite-free.

The Hex Fly Advantage

The Hex fly is shaped like a hexagon with catenary cuts (curved edges that prevent flapping). This design provides excellent coverage for the weight.

I have ridden out several thunderstorms in this setup. The key is pitching the Hex fly with the right angle. I aim for about 30 degrees from horizontal. This creates enough tension to shed rain and wind while maximizing interior space.

In one memorable storm on the Appalachian Trail, rain fell sideways for three hours. Water hit the ground underneath the fly, but I stayed dry. The only issue was some splashing on my feet when the fly was pitched too flat.

A good alternative for your waterproof fabrics research is understanding the difference between silnylon and polyester. The Hex fly uses silnylon which is lighter but can stretch when wet. This means you may need to retension during prolonged rain.

Setup Process: Mastering the Learning Curve

How long does it take to set up a Hennessy hammock?

My first attempt was frustrating. I did not understand the ridge line concept. I hung the hammock too tight. I could not figure out the right distance between trees.

After helping three friends set up their first Hennessys, I have identified the common mistakes:

1. Hanging too tight: The suspension should have about 30 degrees of sag when you are in it. Too tight and you will feel squeezed.
2. Trees too far apart: Ideal distance is 12-15 feet. Much beyond 18 feet and the included ridge line may not reach.
3. Fly pitched too flat: This causes water pooling. The Hex fly needs angle for proper drainage.
4. Not checking above: Always look for dead branches before hanging. I use a bushcraft pants pocket knife to trim small hazard branches when legal.

Step-by-Step Setup Guide

1. Find suitable trees: Look for healthy trees 12-15 feet apart, at least 6 inches in diameter.
2. Wrap tree straps: Wrap each strap around the tree at roughly head height or slightly higher.
3. Attach suspension: Clip the hammock to your straps using your preferred method.
4. Tension the ridge line: The Hennessy should have a gentle curve when empty. Not tight like a guitar string.
5. Attach the Hex fly: Use the provided clips and guy lines. Pitch it with angle for rain shedding.
6. Stake out the sides: Use the side pull-outs to create interior space and keep the netting off your face.

For tarp camping safety, never cook under your hammock fly. Carbon monoxide buildup and fire risk are real concerns. Set up a separate cooking area at least 10 feet from your sleep system.

Comfort and Performance: Sleeping in the Hennessy

Is the Hennessy Ultralite good for side sleepers?

I am primarily a side sleeper, and the first two nights were an adjustment. The key is finding the right diagonal angle. Too much diagonal and your feet press against the netting. Not enough and you get that banana curve.

The sweet spot for me (5 feet 11 inches, 175 lbs) is about 45 degrees off center. I place my head toward the zipper side and my feet toward the opposite corner. This creates a surprisingly flat sleeping surface.

Shoulder room is adequate but not generous. At 18 inches wide in the shoulder area, I have room to shift positions. Taller users over 6 feet 2 inches may feel cramped, especially in the foot area.

Temperature Considerations

Hammocks run cooler than tents. You are suspended in air, so cold air circulates beneath you. This is great in summer but problematic in shoulder seasons.

For temperatures above 60 degrees, the Hennessy is comfortable with just a light blanket or sleeping bag types that work well for hammock use. Below 60, you will want insulation underneath.

The down vs synthetic sleeping bag debate matters here. I use a synthetic underquilt for moisture resistance in damp conditions, paired with a top quilt for temperatures down to 40 degrees. Below that, a full quilt system is essential.

Trying to sleep in a hammock without under-insulation in cold weather is miserable. I learned this the hard way on a 45-degree night. Despite a 20-degree sleeping bag, the cold air from beneath kept me awake shivering.

Weight and Packability: The Ultralight Advantage

This is where the Hennessy Ultralite earns its name. The complete system weighs approximately:

• Hammock body: 18 ounces
• Hex fly: 8 ounces
• Ridge line: 4 ounces
• Total suspended weight: ~30 ounces

Add your tree straps and you are looking at roughly 2 pounds total for a complete sleep system. Compare that to most ultralight tents which start at 2.5-3 pounds and often require a separate footprint.

The packability is exceptional. The entire system stuffs into the included stuff sack which measures roughly 6 x 4 inches. It disappears in a pack, leaving room for other gear. When I am counting grams for a long hike, this compact size is almost as valuable as the low weight.

For reference, a typical one-person tent like the Big Agnes Copper Spur packs to roughly the size of a football. The Hennessy packs closer to a large grapefruit.

Durability and Materials: Built for the Long Trail

The 40D ripstop nylon represents a thoughtful balance between weight and durability. After 60 nights of use, I am seeing minimal wear. The fabric shows no signs of delamination, and all seams are holding strong.

I am particularly impressed with the zipper. After hearing concerns about zipper durability on hammock forums, I have been extra careful. The zipper has held up fine, though I have learned to release tension before zipping from inside.

The ridgeline is a potential weak point. Mine is still intact, but I know several thru-hikers who have replaced the stock ridgeline with Dyneema or Zing-It for additional strength and weight savings.

Hennessy offers a repair service for their products. This is worth considering if you plan to put serious miles on the system. The company has been around since 1999 and has a reputation for standing behind their products.

Detailed Review: Hennessy Ultralite Asym Zip

Hennessy Ultralite Asym Zip - Premium Ultralight Shelter System

The Hennessy Ultralite Asym Zip represents purpose-built engineering for long-distance hikers. Every gram has been considered. The asymmetrical shape is not marketing fluff. It genuinely creates a flatter lay than traditional hammocks, allowing comfortable diagonal sleeping.

The integrated mosquito netting is a standout feature. Many ultralight hammocks require a separate net, adding weight and complexity. Hennessy's design incorporates full bug protection into the main body. The no-see-um mesh is fine enough to block the smallest biting insects while maintaining decent airflow.

I have spent nights in mosquito-heavy areas where tent campers were being eaten through mesh walls. The Hennessy's bottom entry design means bugs never have an opening to exploit. When you are inside, you are fully sealed.

The Hex fly is well-matched to the hammock body. The hexagonal shape with catenary cuts provides excellent coverage without excessive weight or windage. I have experienced winds strong enough to snap tent poles. The Hex fly absorbed the gusts without drama.

For temperature management, the system excels in three-season use. The elevated position creates natural airflow that keeps you cooler than a tent in warm weather. This same airflow becomes a liability in cold conditions without proper insulation.

The build quality reflects years of refinement. Stress points are reinforced. Seams are clean and secure. The zipper, while sometimes stiff under tension, shows no signs of failure after extended use.

Alternatives to Consider

The Hennessy is not the only premium hammock on the market. Here are the main competitors worth considering:

Warbonnet Blackbird

The Warbonnet Blackbird is probably the closest competitor in the premium asymmetrical category. It uses a top entry instead of bottom entry, which many users prefer. The shelf pocket system is brilliant for storing gear.

Trade-offs: The Blackbird typically costs more and has longer lead times. Customization options are extensive, which can be great or overwhelming depending on your preference.

Dutchware Chameleon

The Chameleon takes modularity to the extreme. You can swap components, change the entry style, and essentially build your perfect hammock over time. The weight can be incredibly low with the right options.

Trade-offs: The a la carte pricing adds up quickly. You need to know what you want, or you will end up buying components twice.

Grand Trunk Nano 7

For budget-conscious buyers, the Nano 7 offers ultralight weight at roughly half the price. It is a simple, functional hammock without integrated netting or sophisticated rain fly.

Trade-offs: You will need to purchase netting and fly separately. The build quality does not match premium options, and long-term durability reports are mixed.

Frequently Asked Questions

Final Verdict: Is the Hennessy Worth It?