You're two hours into the climb. It's a bluebird, and it's been cooking since the trailhead. Your kit? Soaked. The smell? Not talking about it. You hit the ridge, start the descent, and land in the shade. The temperature drops ten degrees in thirty seconds. The wind hits your wet back. Your synthetic jersey smiles at its old friend, the sweat-chills.
Lucky for riders everywhere, Merino has been doing mountain weather and stop-go activities since before bikes existed. Yessir, Merino's not just for base layers and grandad sweaters: it's also for ripping bike trails at pace. Punishing climbs, cool descents and ridgeline lunch breaks alike. In fact, that's where it thrives.
Why synthetic jerseys fall short on the trail
Here's the thing about synthetics: they're okay, in the narrow lane they were designed for. If you're into plastic. That's because synthetic fibres were designed for sustained, predictable exertion – not stop-go activities.
Sure, they can wick sweat when you're going hard. But what they don't do, is regulate when you stop. The moment you hit the brakes, or the shade hits, or your heart rate drops on the descent, they stop working. You get cold fast. You get there soaked. And you'll smell like a locker room before the second climb. But up until yours truly entered the bike scene, there hadn't been a great alternative using natural fibres.
Merino, on the other hand, was made for temperature regulation. Which makes it perfect for trail riding – because trail riding isn't one effort, at one pace, in one temperature. It's stop-go. It's punishing climbs in the sun, shaded chutes where the wind bites, long traverses where you're barely moving. Synthetics do alright on the uphill – Merino bike clothing performs all ride long.
Let's get nerdy: How Merino handles the temperature swings of trail riding
So, how does it work? Think of Merino wool as nature's thermoregulator.
The fibre itself is hygroscopic, meaning it absorbs moisture before it reaches your skin, then releases it gradually as your body temperature changes. It responds to conditions in real time: on a hard climb, you stay dry. On a cold descent in the same jersey, you stay warm. It doesn't just wick sweat away from your skin, it actively manages it, which in turn, regulates your temperature in stop-start activities like synthetics couldn't dream.
The lab coats have now caught up, too. A four-year PhD study led by NC State University and The Woolmark Company put numbers to what riders already knew: Merino buffers moisture 96% better than polyester. No chemical treatments. No synthetic additives. Just a fibre doing what it's done for thousands of years on the back of a sheep in the Southern Alps of New Zealand.
Odour resistance: the multi-day riding case
Look, we'll be the first ones to tell you that Merino solves the stink problem. And that's not talk. It's chemistry.
Synthetic fibres trap and hold odour-causing bacteria on the surface of the fibre. One big session, and you'll smell it. You can forget packing light on your multi-day bikepacking trips.
Merino, on the other hand, has a fibre structure naturally resistant to bacterial build-up. It absorbs moisture vapour into the core of the fibre rather than letting it sit on the surface, which means less bacterial activity, and less stink. Ride hard, air it out, ride again.
Merino vs Synthetic: durability on the trail
So, why aren't our bike jerseys 100% Merino? Pure Merino is soft and light, which means it can wear faster than a technical synthetic in abrasive sports. So, we use a small amount of synthetic materials to make sure our jerseys go the durable distance, with stretch that snaps back into place and can handle real trails. But, we wrap that synthetic in Merino to make sure we're getting all the temperature-regulating, odour-resistant benefits of wool next to your skin.
Our Diversion Merino Bike Jersey, for example, uses a blend of Merino, recycled polyester and nylon. Think a four-way stretch, bonded neckline, and breathable mesh underarm panels. With all the perks of Merino. It's built by riders, for riders.
What to look for in a Merino MTB jersey
Not all Merino bike jerseys are created equal. Here's what to look for:
- Articulated fit. Cut for riding, not standing in a shop. Drop tail, contoured panels, nothing riding up your lower back or rubbing under a backpack.
- Merino blend. For trail use, a Merino blend with recycled synthetic adds durability without losing the temperature regulation you came for.
- Details that earn their place. Rear pockets, goggle wipe, dropped hem. Signs it was designed by riders, not for a product shot.
- Weight. Lighter is better for climbing. If you're adding a wind layer for descents, your jersey underneath should breathe, not trap heat.
The Diversion jacket: ISPO 2024 winner explained
Yes, our Diversion Merino Wind Jacket and Diversion Merino Trail Pants both took category wins at the 2024 ISPO Awards. Yes, we're still talking about it. And yes, they look good. But that's not what brought home the gold. That was the wildly innovative technical engineering that did that.
Developed through years of athlete testing in Squamish and Wānaka, the Diversion is built on Mons Royale's Merino Shift fabric: a Merino, recycled polyester, and nylon blend that regulates temperature and dumps sweat. Pertex® Quantum wind panels placed exactly where the wind hits hardest on the ride. A jacket that packs into its own hood. A hood that fits under a helmet. A drop tail that keeps your lower back covered in the drops.
The ISPO jury doesn't hand out awards for products that only look good on paper, or commuter jackets dressed up for trail. It rewards products built on the trails, for the trails.
The full Mons Royale bike range
Quick session jersey or full multi-day riding kit, our Merino bike clothing delivers blends built for the longer ride. Whatever the mission. The Diversion Capsule is the top of the range, but the full Mons bike line covers Merino MTB jerseys, shorts, pants, wind layers, all designed for people who ride hard and need gear that keeps up.
Go on, keep up.
