The Klim Baja S4


Here it is the 2020 Klim Baja S4. This jacket comes in at around the $550 price point and is available in 4 colors Monument Gray, Sage and Strike Orange, Gray and Electric Gecko, and this color here Black and Kinetic Blue. The name harkens to the famous Baja 1000 race on the Baja California Peninsula. If you’ve never been, it’s mucho caliente! It’s no surprise then that the Baja S4 is a Summer/warmer weather riding jacket, geared to the more aggressive adventure rider. Klim confirms this in their marketing materials, letting us know that the S4 was “born for open deserts and towering sand dunes.” We think it fits many more applications, but sure, this jacket does shine in the hot summer weather. In what way you ask? Well, this here is one of the more feature-laden MESH jackets on the market… what’s more, the design is genuinely comfortable. The “S4” in the name stands for 4-way stretch…clever AF! Klim claims the jacket delivers this thorough comfort for hot weather adventure riding, so let’s see what she’s got!

Shell and Construction

Klim constructed the skeleton of the Baja S4 with Cordura 750D material at the Cuffs the Hem and the Cargo pockets. Already somewhat impressed that Klim has chosen to use Cordura 750D here when some other manufacturers use weaker weight fabric in their abrasion zones! The majority of this jacket is built out of Schoeller Dynatec Mesh. This mesh is the primary source of the airflow into the Baja S4. Large panels of Dynatec mesh are located on the chest, the arms, and the back. The mesh not only serves as the venting medium but also as a structural component of the jacket. Isn’t a mesh fabric too weak to do this? What the hell is this Dynatec you speak of? Dynatec is a high tenacity polyamide that employs a unique fabric construction that ensures durability and abrasion resistance. Klim says this is stronger than the Karbonite Mesh used in their Induction Jacket. Alrighty. The main Mesh zones are connected to lower abrasion zones with Klim’s own Karbonite Micromesh 1000D fabric. Although Micromesh has an impressive weight, it isn’t terribly abrasion-resistant. Klim employs Micromesh here to add stretch and breathability to the jacket. It does this well. In the abrasion zones…wait for it…Superfabric! Awesome sauce! We love Superfabric for its abrasion resistance, especially if you take a fall on the road. Slip, not grip, that’s what we want. Snapshot on super fabric: a heavyweight polyester fabric overlaid with tiny “guard plates” that still allow the material to be flexible while providing superior abrasion resistance. Whew. There is Klim’s comfort mapped mesh shell liner and the antimicrobial, anti-odor Polygine micromesh liner in here too. The collar features a comfort liner material similar to a microfleece. 

3m Scotchlite C790 Carbon Black Reflective material, placed in that Biomotion Recognition pattern, making you MORE visible to deer…is splashed around the jacket at the arms, elbows, chest, and back. Biomotion…you deduce.


On the storage front, there are six external pockets. This jacket is no slouch. Starting with the emergency stash Stat card pocket on the left wrist, the jacket moves on to the two front cargo pockets. Not waterproof, but nice to have. Behind those, a couple of hand pockets, for when you want to keep your hands out of the cold summer air. The sixth pocket is this big old rabbit pouch pocket, where you throw a liner or a small hoodie. On the inside of the jacket, two big drop pockets that are perforated to allow for airflow. There is an upper chest pocket, a hidden document pocket, and this compound back pad and Hydration bladder pocket to accommodate Klims 2L Hydrapak. Cool. But wait…there’s more! These two zippers aren’t pockets; they are the openings for a Kidney Belt Channel! “Kidney Belt sold separately.”


Not a ton going on here, but what is here is application-based: aggressive adventure riding. There are adjustable forearm straps to help hold your armor in place…just in case you haven’t been keeping on top of your forearm curls. There is the Bungie adjustable bottom hem to keep dirt and water out; we like these for adventure jackets, no straps getting snagged on branches here! There are adjustable velcro cuffs at the wrists. The jacket comes with a zippered connector that attaches to the S4 pants, or you can sew to the pants of your choosing with the included zippered strip.


The Baja S4 comes with D30 CE Level 1 LP1 vented shoulder and elbow pads, and a CE Level 1 back pad. The back pad slips right into the jacket’s Engineered Spacer Mesh Backpad pocket. I just like saying that. I know I didn’t need to. The elbow pads are adjustable utilizing Klim’s 3 position velcro adjustable armor pockets. Short arm? No Problem. Long Arm? No problem. No job. Problem. 


This thing is pretty much a wind tunnel. There are no zippered vents because the jacket is one giant zippered vent. Look, you can see the light through this thing! The air even comes through the little micromesh zones! And if the air coming through the mesh wasn’t enough, well Klim gave you this collar tab back system…come on man!

We do need to cover one more thing. KLIM released the Baja S4 in conjunction with the Enduro S4 Jacket (and pants if you opt for the full suit). The Enduro S4 is a fully waterproof shell designed to go OVER the Baja S4 Jacket. The waterproof layer adds an extreme amount of versatility to the Baja S4 consideration if you’re looking at other modular solutions. One downfall, it’s a pricey rain suit at around $300 US. 

Guess that does it

Some people don’t get warm enough weather to have a kit for different times of the year. We get it. Some live in a wet, cold climate. We get it. On the surface, it feels like this jacket appeals to a real niche’ audience. But after digging in, there is a lot of value here for a wide variety of riders. Sure, it’s targeted to a desert adventure rider..but layered properly, this jacket could be a commuter’s paradise from late spring through early fall in most parts of the world. The jacket offers unbelievable breathability and a layer of protection that bests many urban commuter jackets in the same price range.

In the mesh, warm weather adventure riding jacket segment, the Baja S4 is approaching best in class marks. It out features its brand sibling Induction Jacket, rivals the Rev’ It Cayenne, and is only really outdone by Klim’s Adventure Rally Air, which is much more money (when it’s not on sale or going through a cycle clearance). 

Is there room to improve? Sure. All products have room, that’s what design cycles are for. We’d like to see CE level 2 armor at this price point, the addition of full grain leather at the abrasion zones, and…just include the kidney belt already. Of course, all of this comes at a cost, which is what product premiums are all about: differentiation.

We liked

  • High-grade materials
  • Exceptionally breathability

We didn’t like

  • Lower-grade armor at CE Level 1
  • Weight
  • Expensive Waterproof add-on in the Enduro S4