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Reviews > Clothing > Base Layers and Undies > Arc Teryx Rho LT Bottoms > Owner Review by Ray Estrella

Arc'teryx Rho LT Bottoms
By Raymond Estrella
March 19, 2007


NAME: Raymond Estrella
AGE: 46
LOCATION: Huntington Beach California USA
HEIGHT: 6' 3" (1.91 m)
WEIGHT: 205 lb (93.00 kg)

I have been backpacking for over 30 years, all over the state of California, and also in Washington, Minnesota, Nevada, Arizona, Idaho and Utah. I hike year-round, mostly in the Sierra Nevada, and average 500+ miles (800+ km) per year. As I start my 4th decade of backpacking I am making the move to lightweight gear, and smaller volume packs. I start early and hike hard so as to enjoy the afternoons exploring. I usually take a freestanding tent and enjoy hot meals at night. If not hiking solo I am usually with my brother-in-law Dave or fiancée Jenn.

The Product

Manufacturer: Arc'teryx Equipment Inc.
Web site:
Product: Rho LT Bottoms
Size: Medium (also available in S, L, XL and XXL)
Year manufactured: 2005
Weight listed: 177 g (6.2 oz) Actual weight 161 g (5.7 oz)
Colors reviewed: Black and Pumice
Warranty: (from company web site) "We proudly guarantee every piece of equipment we make to be free of defects in materials and workmanship. Any defects in materials or workmanship are covered for the lifetime of the product. Product damage through wear and tear, neglect or misuse can be repaired at a nominal charge."

Rho in black and pumice
Image courtesy of Arc'teryx

Product Description

The Arc'teryx Rho LT Bottoms (hereafter called the Rho or the pants) are "lightweight underwear pant" positioned as a layering piece by the manufacturer. (Note: all quotes attributed to Arc'teryx.) It is made of "Rentex Powerflex", which according to the tag inside the pants is 90% polyester and 10% Lycra Spandex. It has a "Silver ion anti-microbial treatment" that per Arc'teryx "reacts with sweat to cut stink out of the technical equation". (More on this later.) The Rentex Powerflex material is very soft to the touch and feels like a stretchy micro-fleece to me. It has a lot of stretch to it.

Mine are full length, but the company offers it in a boot cut also. (Black only.) At the top of the waist is a 1 in (2.5 cm) band of very thick elastic sewn into it. The bottom of the legs have a 0.5 in (0.75 cm) hem which, while it does not have elastic, is quite stretchy from the nature of the fabric.

On the right thigh area a 4 x 5 in (10 x 12.5 cm) pocket has been laminated (glued) on. It has a horizontal flat nylon zipper that has been laminated also to eliminate any extra seams. The pocket is made from some stretchy Schoeller-type fabric and has the cool looking Arc'teryx skeleton-lizard logo embroidered on it.

The crotch is gusseted with a panel that runs from the knees up. It allows for more range of motion without causing the legs to pull and hitch up.

Every seam on the Rho LT is flat-sewn with a serger. When the pants are viewed inside-out there are no seams that stand out.

Field Conditions

These pants have been used in the winter over most of California, from Mt. San Jacinto to Mt. Shasta. Temps there ranged from 9 F to 40 F (-13 to 4 C). They have been used in the northern third of Minnesota from Itasca to the border of Canada. The temps there ranged from -18 to 40 F (-28 to 4 C). I also used them in the Wasatch Mountains of Utah snowshoeing and hiking. Temps there were in the 5 to 30 F range (-15 to -1 C).

Almost all use has been in/on snow, ice or hard frozen ground.


Over the past few years my backpacking purchases have focused on three things; cutting weight, reducing volume, and fighting funk. The purchase of the Rho LT pants and shirt fall into the Fight-the-Funk category. Winter in my opinion is the smelliest season to hike in. The temperatures (that don't allow me to hike half naked), lack of liquid water to clean with, and the fact that conditions often force me to hike wearing my shell garments even though I am a walking furnace, turn me into a microbial playground. (Unabridged version; in the winter I stink!)

I had been very impressed by the odor fighting properties of the silver-impregnated material used in the X-Static liner socks (see review) I had been using for two years. So when I saw that Arc'teryx had a similar sounding material I decided to go ahead and spend the money (they are quite spendy) to try them out. The results are mixed.

These garments are without a doubt the best base layers I have ever used. The construction has been thought out very thoroughly. The seam in the back is not noticeable when my hip belt is pulled tight, and the seams on the inside of my thighs do not chafe as they are so flat.

I do not know why they added the pocket though. It is not big enough to use for much more than a lip balm, and as it is under my fleece pants and/or winter shell pants it is very hard to get to.

The fabric is very comfortable too. It has almost a "springy" feel to it. It is much softer than the other synthetic fabrics I have in my other base layers. It is warmer than my wool stuff. As mentioned earlier, I am a furnace when I hike. Even in winter I can not go above medium-weight in under garments without broiling in them. These pants are fine for me. Many times I have stripped down to just the Rho and a shell with the side zippers opened in sub-freezing weather. It wicks moisture very well and dries quickly from body-heat when I stop for the afternoon and throw my fleece pants over it.

Unfortunately it has not lived up to my expectations in the odor department. ("The Odor department? Basement level, sir…") It does much better than the polypropylene based garments and their like, that I have used in the past or still own. Enough so that I still use the Rho a lot, but I am far from satisfied. My use of lightweight wool products for 3-season use lately (and the good results from same) has soured me somewhat on the Rho. I will still continue my search for the perfect Funk Fighter Fabric. (Sounds like a Marvel Comic, doesn't it? Odor, POW! Stink, WHAMMO!) Maybe Arc'teryx can change the silver composition of the fabric to add more to it. In my liner socks I can see the silver threads, I can not see anything in the Rentex Powerflex. If they do I will give it another shot.

Pros: well constructed, very comfortable, warm, more odor fighting abilities than most other synthetics.

Cons: expensive, odor fighting abilities not up to my expectations.

This report was created with the Report Writer Version 1. Copyright 2007. All rights reserved.
Read more gear reviews by Ray Estrella

Reviews > Clothing > Base Layers and Undies > Arc Teryx Rho LT Bottoms > Owner Review by Ray Estrella

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