FIRST LAYERS AND UNDERWEAR

Men's MTB Base Layers & Liner Shorts – First Layers by Fox

This category brings together first layers and underwear for mountain biking: the garments you wear directly against the skin under a jersey, shorts or body armour. At Foxracing.si you will find men's base layers, undershirts and padded liner shorts designed for trail, enduro, downhill and everyday riding, for anyone who wants to stay dry, comfortable and chafe-free on long descents and climbs alike.

What this category covers

The first layers and underwear range is built around a few core pieces that work together as a riding system:

• Short-sleeve base layers – the everyday choice for warm-weather riding, moving sweat away from the skin and adding a smooth layer under a jersey or protective vest.
• Long-sleeve base layers – for cool mornings, shoulder-season trail rides and winter, adding warmth without bulk under a jacket or jersey.
• Sleeveless base layers – minimal coverage and maximum ventilation, popular under downhill and enduro body armour.
• Padded liner shorts and undershorts – with a chamois insert that cushions the sit bones and reduces friction on longer rides; worn under baggy MTB shorts.
• Long underpants and tights – full-leg coverage for cold rides and for wearing under trousers or knee protection.

How to choose first layers and underwear

• Fit: a base layer should sit close to the body without squeezing. Gaps let sweat sit on the skin, while a too-tight layer restricts breathing on climbs. Liner shorts should stay put without rolling up the thigh.
• Fabric: synthetic knits (polyester, polyamide, elastane) dry fast and are easy to care for; merino blends manage odour and temperature well on multi-day trips. Look for moisture-wicking, quick-drying constructions.
• Season: choose lightweight, highly breathable fabrics and short or no sleeves for summer, and warmer, brushed or long-sleeve layers for autumn, winter and alpine descents.
• Chamois pad: think about how long you ride. Thinner pads suit short, aggressive laps; thicker, multi-density inserts pay off on all-day trail and marathon rides.
• Seams and waistband: flatlock or bonded seams and a soft, non-slip waistband prevent hot spots, especially under a hip pack or protective shorts.
• Armour compatibility: if you ride with a chest protector, spine guard or knee pads, a smooth, slim base layer stops the protection rubbing directly on the skin.

Brands

Fox is the brand behind this category. Fox base layers and liner shorts are made for mountain biking, so cuts, fabrics and pad shapes follow the riding position and work with Fox jerseys, shorts and protection.

Frequently asked questions

Do I wear underwear under padded liner shorts?

No. Padded liner shorts are designed to be worn directly against the skin. Ordinary underwear adds seams and holds moisture, which is exactly what causes chafing.

Do I need a base layer in summer?

Yes, a lightweight one helps. It pulls sweat off the skin so your jersey does not cling, and it adds a comfortable barrier under body armour or a backpack.

What is the difference between liner shorts and MTB shorts?

Liner shorts are a close-fitting, padded underlayer. MTB shorts are the outer, more durable layer that handles abrasion and weather; the two are worn together.

How should a base layer fit?

Snug over the whole torso with no loose folds, long enough to stay tucked in when you are in the attack position, and with sleeves that do not bunch at the elbow.

How do I care for base layers?

Wash them after every ride at a low temperature, skip fabric softener as it clogs the fibres, and let them air dry to preserve elasticity.

Browse the men's first layers and underwear selection at Foxracing.si and build the layer that sits closest to your skin – it is the one that decides how the whole ride feels.