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Knox Zephyr Summer Riding Jacket Review

Product: Zephyr Summer Riding Jacket
Manufacturer: Knox
Made In: United Kingdom
Sizes: Small to 5XL
Color(s): Black, White and Black
Price: £229.99 (GBP) from Knox / $330.00 (USD) from Revzilla


Summer riding gear is always a compromise. Protective riding gear typically requires lots of ventilation for hot weather riding which means mesh materials and/or vents be incorporated into the design. This amounts to a lot of holes which, let’s face it, are going to reduce the integrity of the garment as “air” is not a very good barrier to abrasion.

Full mesh jackets will typically offer the best ventilation for street riding but there are some downsides to the typical mesh jacket. One, most mesh will tear up much faster than a solid textile or perforated leather. Two, all mesh jackets I’ve encountered tend to be a bit loose fitting and the shell is very pliable. This can allow shoulder and elbow armor to move in the event of a crash so it may not be in the ideal position to protect from impact.

Adding solid textile and/or leather to impact zones can help improve abrasion resistance performance at the expense of ventilation. This compromise does improve abrasion resistance but it may not address the often “loose” fit of these type of jackets.

To get around this some riders will go “off label” and use gear that may not be designed for the street or that is not designed to be used as standalone protection. The former often consists of armored off road jackets or shirts where hard armor is attached to a thin mesh shell to provide impact protection. These are typically designed to be worn under a jersey and are not necessarily designed for protecting riders from the types of crashes that can occur on the street.

The latter “off label” item is the armored shirt. These shirts comprise a thin textile shirt with impact protection armor like one would find in a street riding jacket. The protectors are usually softer and designed for the higher speed impacts that can occur in a crash on the street. The problem here is that there is little to no abrasion resistance as these shirts are designed to sit under a proper street riding jacket.

The drawbacks mentioned above are not always enough to deter some riders from going those routes in order to beat the heat. Those willing to accept the risk will wear these items and hope for the best. If there was only a happy medium….

Well, maybe there is.

The Knox Zephyr Summer Riding Jacket

Knox is one of the leading manufacturers of armored shirts, in addition to other protective riding gear,  that I mentioned earlier. As such they often received inquiries regarding the use of their armored shirts alone for upper body protection when street riding. Of course Knox couldn’t recommend this practice as the shirts just wouldn’t offer good abrasion resistance.

Seeing a trend in this, Knox decided to do something about it. Could they take the minimalist approach of an armored shirt and make it tough enough to standalone without the need for a abrasion layer on top? I think they did.

The result is a lightweight hybrid mesh/textile jacket that fits snug like an armored shirt. Add in Micro Lock armor at the shoulders, elbows, and back and you have the svelte look and feel of an armored shirt with durability of a jacket designed for the street. This is the Zephyr Summer riding jacket and it is nearly everything I was looking for to tackle the heat and humidity of a Tennessee Summer.


At first glance the Zephyr Summer riding jacket looks like a slim fitting windbreaker. There are two color schemes with an all black version and a black and sand (tan) version. I chose the sand version as it adds some visibility compared to the stealthy black version. With the intended use being hot weather riding, light colors also seemed to be the best choice.

Up front there are two small hand warmer pockets which, let’s face it,  with their thin lining aren’t going to do much “warming”.  These pockets are best suited to a wallet or maybe a small phone but the snug fit of the jacket means these pockets may not get used for much.

There is a rear pocket that is sewn into the lower portion of the mesh on the back. Knox refers to it as “concealed” and the all black mesh area does make it difficult to point out, but concealed may be a stretch. It does have a decent amount of space and is designed to carry the optional Zephyr Waterproof Overjacket.

If rain protection is needed, an outer layer will have to do the job as there are no provisions for zip in liners. The Zephyr appears to be purpose built to tackle hot and dry weather only but its slim fitting design also means it should fit under warmer and/or drier outerwear quite easily.


The outer shell of the jacket is made from two materials, a tough, stretchy nylon fabric and Arrownet polyester mesh. These two materials, plus the thin cotton lining for the mesh, make for a very lightweight jacket at just 2 lbs 3.4 oz’s (1003g) without armor . Of course one might never realize how light it is until the armor, which at 2lbs and 8 oz’s (1134g) by itself,  is removed and we’ll get to that in a minute. 

Used for the shoulders, sides of the torso, and the outside facing portions of the arms the high tenacity nylon stretch fabric feels tough. It has a good amount of stretch to it but it doesn’t stretch easily so sleeves for instance, aren’t going to “roll” around the arms in the event of a crash.

The black mesh material used in the Zephyr jacket has an open weave which has a bit if a rough texture to it. This roughness is probably why Knox chose to line the mesh areas with a thin layer of soft cotton. In practice it seems to work as I never noticed the rough feel on my arms when wearing this jacket.

Up front there is a YKK Vislon zipper for the main closure and the same type zips are used for the pockets. The interior is all business with no interior pockets save for the ones holding the shoulder and elbow armor. There isn’t even a hang loop on the interior but instead there is one on the outside. It’s a bit of odd placement but it works.


Branding consists of one small rubber patch over the left breast with the Knox logo embossed in it. One would be hard pressed to read it without being very close to the wearer. I prefer this low key approach but I have had so many other riders ask me what this jacket is that I maybe it would have been nice to have a large “Knox Zephyr Summer Riding Jacket” label on the outside.

Stitching and construction on the outside are excellent with nice even seams and no pulled threads to see. The cut of the panels also seems top notch. Looking at the interior it’s not quite as neat. Stitching between the fabric panels is still well done but the trimmed edges aren’t as “clean”. I don’t feel this reduces the strength or durability but might be more of a case of “it’s not going to be seen from the outside” so it’s not a concern.

Despite my picking at the interior seam trimming the overall construction is very good and should prove to be very durable.

Protective Features

Being a Knox product I expected protection to be the focus of the Zephyr jacket and for the most part it excels in this area. As mentioned above, the solid textile areas are made from a high strength, tear resistant nylon fabric. It can be easily distinguished from the mesh in this sand colored version that I purchased. There aren’t any specific details about this material available from Knox but it is supposed to offer “superior” abrasion resistance.

They don’t say superior to what exactly but in the hand the material does have a very durable feel to it and Knox says this material was chosen for “its significant strength, durability, and elasticity”. The last factor might not seem important but I think the stretch of the fabric can contribute to abrasion resistance on rough surfaces as the “give” helps absorb energy that might otherwise cause immediate tearing in less forgiving fabric.

Regarding the mesh material I was keen to learn more about the Arrownet mesh fabric as it sounds like a proprietary material that perhaps Knox developed in house. It turns out it is not a Knox developed material but it is definitely not your average mesh fabric either. While they wouldn’t say exactly from whom the material is sourced, they did tell me that it is a 400GSM (11.8oz) 100% polyester mesh and it has a tear/rip resistance of 100N’s.

The Knox advertising video for the Zephyr jacket claims this mesh material is also used in military applications. Some quick searches on the interwebs found some materials very similar in spec to Arrownet from UK sources (where Knox is headquartered) that provide high durability materials for military and industrial uses.

Suffice to say that I believe the jacket shell should prove to be pretty tough, in fact, likely much tougher than its light weight would suggest. With all that out of the way, let’s look at the armor.

Knox has included their latest MICRO LOCK armor in the Zephyr Summer Riding jacket. This armor is made from a viscoelastic (or similar) type of material so it remains flexible until it encounters sudden force. It then stiffens up to resist flex and disperses the energy of the impact to protect the area directly below from the impact force.

The MICRO LOCK elbow and shoulder armor is very flexible and light coming in around thirty percent lighter than the equivalent previous generation Knox Flexiform armor. These pieces are all CE Level 1 certified so they are light and thin which complements the minimalist goal of the jacket.

For back protection, Knox threw out all the stops and included a CE Level 2 back protector. This protector also uses the new MICRO LOCK technology but since it is Level 2 it is large and heavy. It isn’t uncomfortable despite the bulk and is probably the most flexible and well ventilated back protector insert I’ve handled.

The yellow material is super soft. One can easily roll it up, twist it, and “smush” it up nearly any way desired. It feels ridiculously flexible and the large area of cutouts for ventilation enhance this flexibility. Those cutouts are great at moving a lot of air bu,t in order to meet CE Level 2 protection, the protector ends up being pretty stout at a full inch thick (24mm).


So all around, the protection is very good, but one thing puzzles me. Since we already have a large and heavy CE Level 2 back protector, why not just include CE Level 2 shoulder and elbow armor as well. Yes, it is about one third more weight than the Level 1 pieces and a little thicker, but would anyone notice the extra weight at this point? I reached out to Knox to see if their Level 2 protectors would fit  in the elbows and shoulders and their reply was,

 “CE Level 2 Parts 363 and 362 will fit into the Zephyr, but they are slightly thicker and slightly heavier than CE Level 1 so may alter the fit, especially under the arms.” 

I might have to grab a set and see how they fit.

Fit and Comfort.

Describing the fit of the Zephyr jacket is easy, snug. If one likes and appreciates a cozy fit to their riding gear, the Zephyr has it in spades. This is not unexpected as the jacket is supposed to be close fitting and this is important for keeping the armor properly located in the event of a crash.

With a 41 inch chest I typically sit right in the middle between medium and large sizes in many jackets. According to Knox’s size chart I should be wearing a large which is what I have and is pictured here. When I first put it on I wasn’t sure it was going to zip up but once I joined the zippered edges and started pulling up the zipper the jacket stretched to fit.


I mentioned earlier that the stretch material doesn’t stretch too easily. It has some good resistance and feels a bit like a light compression shirt once zipped. The snug fit doesn’t affect range of motion needed for riding and the jacket moves quite well with the wearer.

The sleeves are precurved for the riding position and this is where the jacket is most “relaxed”.  The only area that gets a little “weird” is the shoulder armor. Raising one’s arms over shoulder height will get the armor up on its edge. Since one doesn’t often reach up high when riding it doesn’t really become an issue. Riders of bikes with ape hanger bars need not apply.

There is little in fit adjustment needed on the Zephyr jacket due to the stretch function of solid textile areas. There are, however, two snap adjusters at the waist with a two position snap strap that for tightening up the lower edge of the jacket. The sleeve cuffs also get a two position snap strap to ensure the sleeves stay snug against the wrist/forearm area.


With Arrownet mesh making up most of the front and rear and of the torso as well as the inside facing sides of the sleeves, the Zephyr flows a good amount of air. With the large weave of this mesh good ventilation is not surprising.

It would likely improve a little more if the thin cotton liner wasn’t in place but I understand why it’s necessary. This mesh isn’t as soft as the type used in say, the Joe Rocket Phoenix series jackets, so having this liner between the rougher mesh and one’s skin is probably worth it for comfort.

The biggest concern for me was the very large back protector and how it might prevent airflow. This is the most significant compromise I feel had to be made in the design of this jacket. In order to provide CE Level 2 protection the protector has to cover a large area and provide significant impact absorption.

Since this is going in a hot weather jacket there also needed to be a lot of venting which meant the removal of material for air passages. As more venting is created, the remaining material has to be thicker in order to provide protection. The resulting protector does allow for a good amount of airflow and the expense of significant weight of 1lb 12oz (794g).

Is it worth it?

I’d say so. I purchased this jacket specifically for the increase in airflow I needed to counter the decrease in venting I get from wearing my Hit-Air MLV-C airbag vest. I intended on wearing the Pilot Elipsol jacket that I reviewed  for webBikeWorld this summer but the vest covered the jacket’s mesh panels to the point is just didn’t breathe much at all. That’s when I started looking for a new mesh jacket and landed on the Zephyr.


At $330.00 (USD) the Zephyr Summer Riding jacket is not inexpensive, however, I feel like I have gotten what I paid for and maybe a little more. When viewed through the lens of the materials used and cost of manufacturing the value may appear a bit average but the Zephyr is more than the sum of its parts.

I searched quite a bit for a jacket that combines all the qualities I was looking for in a hot weather riding jacket and the Zephyr pretty much nailed it. Large areas of durable mesh, fully kitted out armor, and a close fitting design were not that easy to find elsewhere. Maybe the Dainese Sport Guard jacket would be a close rival but I didn’t care for the style of that jacket.

And that’s another thing. I think the Zephyr Summer Riding jacket in this sand color looks good. This is of course subjective but other riders have commented on the looks. The jacket has some style to it without needing shouty graphics or metal covered shoulders. The Zephyr jacket is proof that sometimes less really is more..


  1. Urs Luescher

    Thanks for the review! It goes along with my experiences. I bought the Zepyr Jacket back in March and have been using it here in Switzerland for spring and now summer riding. Even in the hot summer we have right now, I am using the Jacket in combination with an outer shell jacket – in oder words my use case is more towards the armored shirt side of things. In an offroad scenario or small and slow tarmac roads I would use it standalone. The combination that works for me is the Knox Zephyr with a Klim Marrakesh on top.

  2. Kit Carpenter

    I appreciate this thorough review. How is the Jacket two years later?

    • Brandon

      It is great! still looks good and I love it. However, I may be replacing it for next summer ONLY because I have new Klim Ai-1 airbag vest that goes under my jackets. The Zephyr fits me perfectly normally but it is just to snug putting it on over the vest so I’m looking to get the new “pro” version next spring in the next size up. Great summer jacket for sure.

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