Review: Assos X Mammut Hybrid Vest

A good vest or gilet is arguably the most versatile item in any cyclist’s wardrobe, so how does the Hybrid Vest from the Swiss collab between Assos and Mammut measure up?

Why I chose the Assos X Mammut Hybrid Vest

Wardrobe staples for modern tech bros and rugby fans, all cyclists deserve a pass when it comes to gilets. A well-designed gilet, with the right insulation, proper wind protection, and a two-way zip, is one of the most versatile pieces of clothing a cyclist can own and is definitely worthy of a permanent spot in your jersey pocket, bar or frame bag, almost regardless of where you live and what kind of riding you do.

That’s especially true during shoulder season in the UK. There’s a decent chance your ride will stay dry, but keeping your core warm without overheating everywhere else is the trick, and a good gilet is often the simplest solution.

Over the past five years of long-distance rides — usually stitched together with train journeys at either end — I’ve spent plenty of return trips drifting in and out of sleep: my head sliding from palm to window, or balanced on a precariously placed elbow that eventually gives up. Unsurprisingly, it’s this semi-conscious state of being that I can thank for a bad habit of leaving gilets on high speed trains across the country.

The one I did manage to keep hold of was the excellent Odyssey gilet from PedalEd. When the zip finally gave up at the start of last year, it became clear that by autumn I’d need to find a replacement.

Brand collaborations can be a funny thing. Often they feel like a straightforward equation: take one fashion-leaning brand, one technical manufacturer, add a second logo, and hope the combined fan bases do the rest. But occasionally the pairing actually makes sense.

Which brings us to the collaboration between two Swiss heavyweights: Mammut — better known for its alpine heritage and serious down and waterproof outerwear — and Assos, the long-time specialists in high-performance lycra.

The perfect colliding of mountain and cycling heritage, I’d initially had my eye on the down jacket from the same collaboration. But alas, the press samples soon disappeared. The next best thing, perhaps? Enter the Assos × Mammut Hybrid Vest.

Out the Box

Straight away it’s clear this is a more relaxed, generously cut piece. There’s an obvious influence from Mammut here rather than Assos’s typically close, race-oriented road fit. The result feels far better suited to casual riding, touring or bikepacking than fast, high-speed road efforts.

The construction reinforces that impression. Two large chest pockets sit either side of the zip, with no rear storage. The insulation is substantial, with a solid rear panel instead of the ventilated mesh backs you often see on road-focused gilets. The material has a lovely stretch that feels genuinely premium, and the two-way zip is smooth, solid and impressively easy to use.

That might sound like a small detail, but zips on cycling kit can often be surprisingly fiddly. You really notice the difference when you’re trying to reconnect the base one-handed while the crest of a climb is fast approaching.

The other thing you can’t ignore is just how red this thing is. Maybe it’s a nod to the Swiss alpine heritage behind the brands involved, but it definitely gives off strong ski-patrol energy. Thankfully, it’s a look I don’t hate.

Put to the Test

My riding spans a fairly wide range, and my kit drawer reflects that. After a pretty intense summer in 2024 training for and racing the Transcontinental Race, I’ve found myself leaning more toward relaxed rides — cruising into the woods, exploring mixed surfaces, and generally riding a little slower. The riding is less intense, and the clothes are a little less tight.

That shift is exactly where the Hybrid Vest has slotted in during autumn and now into early spring.

I’ve worn it over everything from a simple long-sleeve tee to an insulated jacket, and it works well across that range. Coming from a road background, the front-pocket layout — with nothing on the rear — takes a little getting used to. Leaned forward on the bike, the bulk of a phone or keys can feel slightly awkward compared with the usual rear jersey pockets. In practice it’s rarely a dealbreaker, as I usually have other storage options, but it’s worth noting.

And the pockets themselves are enormous — almost to a fault. Again, this feels borrowed from general outdoor wear rather than typical cycling apparel.

Where the vest really delivers is insulation. The combination of Pertex Quantum Air on the front and Polartec Alpha insulation provides an excellent warmth-to-weight balance, while still feeling impressively breathable. And with such a smooth two-way zip, dumping heat on the move is so easy that breathability almost becomes a secondary concern.

Key Features

Insulation

A combination of Pertex® Quantum Air and Polartec® Alpha® insulation make for a really premium warm option.

Cut and Fit

Obviously longer and more roomy than typical cycling clothing, making it a great option for more chill rides or those who are after a generous fit.

Two-way zip

I could preach for ever on the importance of a two way zip, not only for heat and moisture management but for access too. It’s a must for any outer layer on the bike but it’s amazing how many items still don’t bother.

Pockets

There are two huge chest pockets either side of the zip, although for me personally, I’m not convonced they’re so useful. I think for something of this weight, I’d much rather a zipped rear pocket to keep key things secure and feeling stable against my position - but that’s just me. Others may appreciate the ease of access and room available.

Material

The full body of the gilet is made from a really stretchy material which also feels really durable compared to many of the lighterwight or slightly bin bag feel we see so often in cycling apparel. I wouldnt’ be worried riding off road where there might be high risk of snagging - typical here in the UK – thanks to its ripstop construction.

Pros

Really high quality insulation

Generous longer fit

Sleek feel and aesthetic

Cons

No rear pockets may be an issue for some

Rating

4/5

Is the Assos X Mammut Hybrid Vest worth your money?

At £175 it definitely sits toward the upper end of the insulated gilet market, though that’s fairly typical territory for premium cycling brands. For comparison, the Albion Pertex Quantum Gilet comes in around £135, the Rapha Brevet Insulated Gilet — a long-time personal favourite of mine — retails for about £170, and the PedalEd Odyssey Insulated Gilet lands almost exactly the same at £175.

Against that backdrop, the pricing feels broadly in line with the competition. That said, if you’re looking for something packed with cycling-specific features, there are options out there that may suit you better.

What this vest offers instead is simplicity done well: solid insulation, excellent materials and a relaxed fit that works particularly well for mixed riding, touring and bikepacking. If that’s the kind of riding you lean towards, it’s a genuinely appealing option.

And with current discounts bringing it down to around £123 direct from Assos, it starts to look like very good value indeed.