MTB Specific Windbreaker?

I have the Patagonia dirt roamer which is basically that. They have replaced that model and i suppose the that too is good, but if you can find the dirt roamer at a sale somewhere that's my recommendation.

https://ch.monsroyale.com/products/diversion-merino-wind-jacket-black-mens

the mons or the rapha windblocker jerseys are also really good

Another recommendation for the Mons Royale Tarn merino wind jersey. Doesn't get too hot on the climb up to 15c and the windshield front panel does a great job for the descent.

https://ca.monsroyale.com/products/tarn-merino-bike-wind-jersey-black-mens?variant=44875355947198

Windbreaker vest! Just a simple, light shell. Arc'Teryx used to make one that was perfect, decently durable, but seems to be discontinued. 

Hoods are stupid when riding, which most windbreakers seems to have. 

I need to replace my vest, it's pretty shredded. Anyone know of others? The roadie cut stuff is a hard pass.

I have fox vest that I more or less use as a high vis vest since there’s hunters many places I ride.  The pull tab on the tiny zipper broke but it still works just fine.

Second the Dirt Roamer. My son and I both use them. I found one off Poshmark fairly cheap and another one a closeout sale. They’re pretty great. 

I have a fox Ranger wind jacket and it's been excellent for those kinda days, going on 5 years old.
I have a second one I wear as casual aswell.

I am also a fan of the Rapha windblock jerseys. And when it gets a little colder but not too cold for the big guns, yet, a Giro Cascade vest is a great extra layer that doesn't make me sweat like a pig.

For the few months a year here where it's something resembling cold in the morning, I like to start with a Patagonia Houdini pullover windbreaker (not the full zip, since it has a hood).  It stuffs into it's chest pocket, which then fits nicely into in-frame storage.  (BTW, that's the best use I've found for in-frame storage, as the windbreaker weighs next to nothing and doesn't rattle around.)  Windbreakers warm you up surprisingly fast when you're moving, as they act as a vapor barrier and trap all that warm, moist air your body generates.  I usually start with it on for about 15 minutes until I warm up, then take it off for the rest of the climb, and put it back on for descents.  You can often find past year's colors of the Houdini on sale.

The Rapha windblock jersey is nice but I think it's less versatile than a packable ultra light windbreaker, since you're stuck wearing it even when you warm up or the temps climb.

patagonia houdini or patagonia airshed pro depending on the temps and amount of preciptation or dew/moisture that may be present.

I don't have a specific recommendation, but I used to have an old Pearl Izumi vest (90s vintage, so hard to say if it was intended for road or MT that was wind breaker material on the front, and full mesh on the back. Super easy to stash away once you got warmed up, and didn't really get you too hot, so you could wait until you wanted to stop to take it off. Was great for those rides that started on a flat road to the trailhead

Chromag has a good one, no hood. 

The Windblock jerseys have wind blocking fabric only in the front panel, the rest is lightweight breathable fabric, so they are much more comfortable to ride in than generic windbreakers.

I know.  I own one.

I have an Ogio-branded one that works really well. It has no collar, but the neck is tall; when zipped up, it will cover the back of my neck nicely. It's made from really thin, rip-stop material and it will fold/wad up small enough to fit in a large pocket in my shorts. 

I rode in my Fjallraven/Sepecialized vest this morning, and find it pretty darn good. It's looser fit than a roadie best, but not baggy. Fits in its own pocket. I feel like it lets out hot air in the back better than most. It also has up and down zippers. 

If I'm actually in the mountains, houdini or the dirt roamer is my go to. 

I would like to find a vest or jacket that is houdini windstop in the front and then a light weight breathable fabric on the back. That Mons Royal jacket comes in a vest version, and it looks close. How thick/aka hot is that merino fabric? https://monsroyale.com/products/diversion-merino-wind-vest-black-mens

longsleeve mons stuff i usually wear up to 20°C before it gets too hot

7Mesh Northwoods

OR Ferrosi.  Breathes amazing.  Not part of their bike stuff but I'm 100% happy with mine.  Use it almost only for riding 

Patagonia Houdini gets my nod. It's perfectly simple and gets year-round use. It serves as a wind protection layer the winter and an ultra-packable layer to defend against rain and cold the rest of the year. It's not mtb specific, but it's a great piece of gear for any type 2 fun in variable conditions.

Unless you live somewhere it's cool to ride in the rain, don't try be cool by getting a hoodie.  The hood will be an annoying and stupid fashion accessory.

I'd highly recommend the OR Deviator for the jacket.  For a vest I have a Patagonia Dirt Roamer, but I'd look hard at sizing down.  OR Deviator vest is also good, but weirdly has a thicker front than the jacket.  Don't ride in it very much at all.

I also have an old Sweet Protection windbreaker jacket, but I think they went and put a f'ing hood on it, so I wouldn't recommend it.  The currently ubiquitous hoods remind me of the Portlandia "put a bird on it" episode.  Right now, you have to work hard to find a jacket without a hood.

Reading through these primadonna replies is insanity. $80-$150 for a thin piece of plastic?
 Grab a cheap solid black windbreaker at WalMart/Target/CostCo for $25.
They usually stuff in their own mesh pocket. 
Make sure you get one with the vent in the top of the back.  Then if you're sweating, you unzip as far as needed & it dumps heat.

Plus...most people who toss those plastic garbage bags with a hood & a zipper on wind up avoiding them altogether after too many swampy sessions.   

I ride 99% of my rides in jerseys layered from thin to thick if needed. The "Skyline Chill" jersey from TLD on it's own is a great bridge b/c it's relatively warm on a chilly ride (whether you add a base layer or not) and it will still wick in decently warm weather.  

I'd go that route first.  Heck...I can ride in 30 degree WNC temps in that jersey and 20 degrees, I toss on a cheap windbreaker.
Don't burn $80+ until you know it's really for you.

If you want a cheap windbreaker skip Walmart and go to the thrift store.  You will find something much nicer for less.  Plus help the environment.  It’s a win win.

Not try sound elitist here (but I'm sure I'm going to)... as I've gotten older, I've started to focus on buying stuff once and buying it right.  It means I pay more for stuff, but I'm more invested in it and I enjoy the process of identifying my specific needs and sourcing the product that fits that.  That also gives me a chance to support brands that align with things that are important to me like: sustainability, trail/stewardship and conversation, brand identity etc.  This is what has lead me to Ketl, Patagonia, etc instead of disposable, questionable supply chain and worker treatment.  

The end result of this is that I am now invested in the stuff and when I destroy it, I have it fixed by a local seamstress and then it tells a story.  For example, I put a tear in a patagonia Houdini jacket and had a local tailor fix it.  That tailor, also added pit zips to it with color matched ykk waterproof zippers.  Now I have a customized patagonia houdini, that is better then when I got it (ample venting and no trash bag tendencies).  Now it comes with a great story of when I was at whistler bike park and decided to @#$! around and find out by riding Tatiania during a rain storm and discovered I have less talent on the bike then I thought.  

There are many jackets like this one, but this one is mine and I honestly love it.