Acre Supply | District Henley | $140

I was hesitant to review a shirt that costs this much, but because the District still looks brand new after having ridden in it almost exclusively for more than a year now, I've concluded that this seemingly pretentious piece of clothing is worth every damn penny.

It's my go-to for a day on the trail and one of my favorite shirts, period. For every ride the District has been on, there have been at least a dozen more dinner dates, parties, shop days, hikes and campfires. I'm especially a fan of the Henley style. The three buttons don't just look sharp in the city, they do a great job of helping to regulate temperature on the trail. I wear it so much that my coworkers actually believe I only own this shirt, a pair of green Carhartts and a bunch of pajama pants.

Merino has a wide temperature range, wicks moisture well, stays warm when wet, dries quickly and naturally resists odors, but synthetics have wool beaten in the durability game, which is why the District's 18.9 micron Merino has a small amount of Nylon woven into it. It's also a pretty dense weave, at 190 grams per square inch. I've crashed in and washed the District a lot over the past year, and there's not a single pill, hole or frayed thread.

Even though the District gets heavier than polyester when soaked, it never gives you that gross, wet-garbage-bag-against-the-skin feeling and the fibers are fine enough that there's no scratchy wool feeling either. The fit is relaxed, like a T-shirt, and sizing is spot-on. The cut is pretty square and there's no funky drop tail, strange sleeve lengths or oddly placed pockets. It's a simple put-it-on-and-forget-about-it deal, which is surprisingly hard to come by.

I'd gladly bring this on multi-day adventures as my one and only jersey. Actually, I have, and on its own, this single made-in-America shirt is more valuable than a bag full of smelly polyester garbage. —Ryan Palmer

Outlier | Ultrafine Merino T-Shirt | $100

Unlike the vintage Pendleton shirts worn by Portland hipsters in the Poler Stuff store, most modern Merino pieces you'll find are soft on the skin, thanks to fine yarns made with 18.9 micron fibers. Well, Outlier's 17.5-micron Ultrafine Merino Tee makes those feel like steel wool on your nipples in comparison.

Hell, this 100-percent Merino, made-in-America masterpiece makes soft cotton feel downright rough. The Brooklyn-based company set out to make the perfect T-shirt, and it just might have done it. The first time I pulled on the Tee, it stayed on for four days straight. Then it went in the wash and straight back on. I've only had my new friend for a couple months, but I've worn it a lot in that time. One of my favorite things about Outlier is that it doesn't plaster logos on any of its stuff, so you're not paying for a product just to be a billboard for the brand.

The fine wool fibers used to construct the shirt are woven to a density of nearly 200 grams per meter, making it a tight, durable knit that drapes like cotton. It wears like a T-shirt, but it's softer, wicks moisture better, dries faster, doesn't absorb odors and is comfortable in a wider temperature range. It's so comfy that sometimes I find myself reaching for a different jersey to ride in, because the Outlier is the coziest post-ride thing I now own.

But relegating it to non-active duty is not the best plan for a shirt that's made entirely of nature's best performance material. This shirt does its best work when you're producing sweat, whether it's inside a trendy Brooklyn gym, bagging 14ers in Colorado or chasing endless singletrack in the Pacific Northwest. It's a lot to shell out for a high-tech t-shirt, but you get what you pay for. —R.P.

Showers Pass | Bamboo-Merino Henley | $75

To make its Henley feel soft, Showers Pass chose a blend that puts bamboo against the skin. The material isn't just a combination of Merino and bamboo, it's actually knitted in a layered fashion so the Merino faces out while the smoother bamboo fibers face inward.

Bamboo has been making its way into performance base layers for some time because it's a natural fiber that does a decent job resisting odors and wicks well, but is stronger than Merino, holds its shape better and is more affordable. So combining the two should make the most badass, high-tech natural fiber around, right?

For starters, the bamboo feels soft against the skin, but in a much different way than an ultra-fine Merino—it feels a little cooler, almost like a synthetic material. But then the Merino layer gives the jersey some weight and warmth, allowing it to regulate temperature well.

The material definitely works. It provides all-day, itch-free comfort, keeps you warm in shade and cool in the sun, dries fast and doesn't get all funky like polyester. And even though bamboo feels a bit like a synthetic on the skin, it wicks moisture across to the wool layer fast enough that it never really feels cold and wet.

I've haven't owned this jersey as long as the other two, so it's tough to make a direct durability comparison, but it's been holding its shape very well. And shape is something the Showers Pass Henley has more of than all the other Merino shirts I have. It has a slimmer cut with more of a next-to-skin feel, without going full-on race-kit tight. I wound up bumping up a size, and it's still a more tailored cut down the torso than the other two jerseys tested. Keep this in mind when ordering.

This is a great option for anyone drawn to wool but sensitive to it, because it'll give you many of the same properties with a different against the skin feel. Plus, it's the only one out of the three that's also made in a women's cut. —R.P.

Specialized | Andorra Drirelease Merino ¾ Jersey | $80

Including the Specialized Andorra in a test of Merino jerseys could be considered a stretch (excuse the pun). After all, its material consists only of 11 percent Merino wool. The remainder is polyester and a 5-percent touch of Spandex. Still, leaving it out felt like being named team captain in gym class, then not picking your best friend to be on your soccer team. Despite its minimal use of Merino, the Andorra's fit and function constantly keep it at the top of my jersey pile. The cut of the Andorra is perfect—it's not baggy, but not too tight to move with you on the bike—and while I expected the antimicrobial properties of Merino to be sacrificed, I don't appear to smell any worse wearing this jersey versus options with more wool content, however, I did not substantiate that assumption with any of my riding partners. Hands down, the Andorra repels odor much better than a full polyester jersey.

A nice added touch is a side zippered pocket that can fit an iPhone 6, cash and a small gel or bar. I've also been able to cram a tightly wrapped tube in there and a Co2 cartridge, but if you overstuff it, the jersey pulls to left when you're riding, which can be annoying.

I've worn and washed—but only line-dried—this jersey many dozens of times over the past year, and the material has held up exceptionally. There is some pilling around the waist, which is typical of wool and it also happens to be at the precise location where my hip pack buckle rest, so that friction may have sped up the pilling process.

The mid-weight jersey is comfortable in both warm and cool weather, although I logged much more time in it in hot conditions, given my southern California home base. It wicks well, but no wool jersey is ever going to be the draftiest option on the market. Finally, don't let the colors of the Andorra sell you—this is last year's version and Specialized has updated this year's offering with three new color combinations. —Nicole Formosa

Wild Rye | Kiah Tee | $69

Wild Rye's mission is to make women's mountain bike apparel that looks less, well, mountain bike-y. The gals behind the emerging brand, Cassie Abel and Katy Hover-Smoot, certainly achieved that with their debut offering, the Kiah. The material is 89-percent 17.5-micron Merino wool blended with nylon and could easily pass as casual mountain-town evening wear. And that is sort of its best attribute and its biggest challenge. Its light-pink hue, cap sleeves and scoop neck make it so pretty that I find myself worrying about getting it dirty on the trail because I want to wear it to dinner that night.

Not that it can't party in the dirt as well. It's comfortable, true to size and breathable. The material is surprisingly soft against the skin thanks to that fine, 17.5-micron weave. The single left-breast pocket wins style points, but it's not exactly practical, and I personally prefer a longer sleeve for sun protection, but some will prefer a cap sleeve to a tank top. The scoop neck also adds a nice feminine touch, and it doesn't dip so low that you're worried about showing more than you anticipated.

Wild Rye has also done right by women of all body types by offering the Kiah in a full size run, from XS to XL. At $69, it's priced competitively for a top that's nearly 100-percent wool, which may have to do with Wild Rye's decision to sell primarily direct-to-consumers versus through brick-and-mortar stores, which helps keep costs

I've had about six months wearing the Kiah, and it's been through multiple washes and it still looks brand new. This is a testament to the emphasis Wild Rye has placed on quality materials and construction, an attribute also seen on Wild Rye's debut shorts, which are made from high-end Schoeller fabric. —N.F.