FOX BASEFRAME PRO SHORT SLEEVE BODY ARMOR

Fox Baseframe Pro Short Sleeve MTB Protective Shirt

The Fox Baseframe Pro Short Sleeve is a breathable protective shirt for mountain biking, designed for riders who want certified protection for the chest, back and shoulders without the feel of heavy, stiff body armor. It's worn as a close-fitting base layer under your MTB jersey, so the protection stays close to the body, while the stretch fabric and short sleeves allow enough freedom of movement for trail, enduro, bike park and technical riding.

Protection comes from removable Koroyd® inserts with a patented auxetic structure – a special geometric design that adapts under load, combining flexibility with effective impact energy management. The shoulder protection is certified to EN1621-1 Level 1, the back protection to EN1621-2 Level 1, and the chest protection to EN1621-3 Level 1. The mesh construction helps wick away sweat and heat, while the side compression panels keep the protective inserts stable against the body even during fast, dynamic riding.

The Problem: More Protection Usually Means More Heat and Less Movement

For more aggressive mountain biking, protecting the shoulders, chest and back makes sense, but classic protective vests often add a lot of bulk, heat and stiffness. This is especially noticeable on climbs, longer enduro stages and summer rides, where heavier armor can quickly become a piece of gear you'd rather take off.

The Solution: Three Key Protection Zones in One Close-Fitting Base Layer

The Baseframe Pro Short Sleeve combines shoulder, chest and back protection in a close-fitting shirt worn directly under your jersey. The protective panels stay close to the body, while the compression side panels reduce unwanted movement during braking, landings, quick direction changes and riding over rough terrain.

What Does the Auxetic Koroyd® Structure Mean?

An auxetic structure is a special geometric arrangement of the material that behaves differently under load than conventional materials. This internal geometry allows the Koroyd® protection to adapt to the body's movement while still managing impact energy, making it suitable for protective gear where both mobility and impact absorption matter.

Koroyd® Shoulder Protection – EN1621-1 Level 1

The protective panels on the shoulders are certified to EN1621-1 Level 1. The shoulders are often among the first points of contact with the ground in a crash, so the short-sleeve version of the Baseframe Pro offers more coverage than the sleeveless model.

Koroyd® Back Protection – EN1621-2 Level 1

The back protector meets the EN1621-2 Level 1 standard and is designed to reduce energy transfer in the event of an impact to the back of the torso.

Koroyd® Chest Protection – EN1621-3 Level 1

The chest protector is certified to EN1621-3 Level 1 and protects the front of the torso. Combined with the shoulder and back protection, this gives you more complete upper body protection.

Why Do Short Sleeves Mean More Protection?

Short sleeves allow the shoulder protection panels to be integrated without turning the shirt into a full long-sleeve jacket. This is a good middle ground for riders who want extra shoulder protection but still need plenty of breathability and freedom of arm movement.

Mesh Fabric to Reduce Overheating

The main body of the shirt uses a breathable mesh construction that allows airflow and helps wick away sweat during the ride. This is especially important for enduro riding and long climbs, where protective gear can quickly overheat.

Compression Panels Keep the Protection in Place

The side compression panels help keep the shoulder, chest and back inserts close to the body. Stable protection means less shifting during vibrations, quick position changes and riding over technically demanding terrain.

Wide Neckline for Easier Wear Under a Jersey

The wide neckline improves comfort and makes it easier to combine with an MTB jersey. Since the Baseframe Pro is designed as a base layer, it stays visually and functionally unobtrusive under the outer layer.

YKK® Zipper for Easier Putting On and Taking Off

A close fit needs to be stable enough to keep the protection in place while riding. The YKK® zipper at the lower part therefore makes it easier to put on and take off the shirt without needing an overly loose cut.

Removable Koroyd® Inserts for Easier Cleaning

The protective inserts are removable, making it easier to clean the shirt after a sweaty, dusty or muddy ride. This is especially important for protective gear worn directly against the skin.

Who Is the Fox Baseframe Pro Short Sleeve For?

It's suitable for trail, enduro and bike park riders who ride faster, take on technical lines, jumps, rocky sections or longer descents, and want more coverage than a sleeveless protector offers. It's especially useful for riders who want shoulder, chest and back protection in one lightweight, breathable system.

Baseframe Pro Short Sleeve or Sleeveless?

If you want as little material as possible and are mainly focused on chest and back protection, the sleeveless version is lighter and more open around the shoulders. The Baseframe Pro Short Sleeve, on the other hand, adds certified EN1621-1 Level 1 Koroyd® shoulder protection, making it better suited to riders who want broader upper body protection.

Why Choose the Fox Baseframe Pro Short Sleeve?

This is protection for riders who don't want to choose between mobility and coverage. The Baseframe Pro Short Sleeve combines three certified protection zones, auxetic Koroyd® inserts, breathable mesh construction and a compression fit in one piece designed so you can actually wear it throughout the whole ride.

Features:

• MTB protective shirt with short sleeves.
• Shoulder, chest and back protection.
• Removable Koroyd® protective inserts.
• Patented auxetic Koroyd® structure for high mobility.
• Koroyd® shoulder protection: EN1621-1 Level 1.
• Koroyd® back protection: EN1621-2 Level 1.
• Koroyd® chest protection: EN1621-3 Level 1.
• Breathable mesh fabric.
• The fabric helps wick away sweat during the ride.
• Side compression panels help keep all protective inserts close to the body.
• Close fit for a stable protection position.
• Wide neckline for comfort and easy layering under an MTB jersey.
• YKK® zipper for easier putting on and taking off.
• Removable inserts make cleaning easier.
• Suitable for trail, enduro, bike park and technical mountain biking.

Materials:

• 65% polyester, 19% polyamide (nylon), 16% elastane.

Recommended Use:

• Trail MTB.
• Enduro.
• Bike park.
• Technical descents.
• Jumps and more demanding lines.
• Riding where you want shoulder, chest and back protection with minimal restriction of movement.