How to Buy a Cycling Base Layer: Size, Fit, & Style Guide

Posted On November 30, 2022 / Gear Tips

By: Drew Hincapie

cyclist putting on base layer

A cycling base layer is the inconspicuous hero of an enjoyable ride. Base layers provide a barrier between you and the bitter winter chill and keep your core dry in a downpour or an outpour of sweat. There’s a base layer for every season–you can choose from short-sleeve, long-sleeve, or sleeveless base layers in synthetic or natural materials. Base layers help maintain your core temperature and comfort and offer protection from chafing and even road rash. Because there’s much more than warmth to consider, this buying guide covers all the bases (no pun intended), so you can find the best base layer to keep you cycling comfortably. 

What is a cycling base layer?

A cycling base layer is the first layer in a cycling kit. It’s designed to help maintain the body’s core temperature and comfort in any climate. Finding the best type of base layer depends on whether you need it to keep you warm or cool you down. Cyclists often wear one type of base layer in summer and another in winter. A regular cotton undershirt won’t do the trick since cotton retains moisture and bunches up, but the fibers in a base layer wick moisture and won’t bunch or chafe if it’s fitted well. 

Cycling base layers for cold weather

In winter, wearing a base layer is a necessity. Winter base layers provide a low-profile layer of insulation under your cycling jersey. They’re excellent for adding warmth without adding bulk. Cold-weather base layers trap warmth from your skin and dispel sweat that would cool your core temperature. Base layers are great at insulating but not protecting against wind, which is why they should be worn under a cycling jersey and jacket in winter. 

A base layer is just one of many winter cycling essentials. Learn how you can prep for winter riding with the best cold-weather cycling gear

Cycling base layers for warm weather

In theory, summer cycling base layers cool you down by aiding the body’s natural temperature regulation process. As your body starts to warm up, it begins to sweat to release heat. As the sweat evaporates, it cools you down. The base layer absorbs the sweat and transports it away from your skin and to the outside of the moisture-wicking material to evaporate. The more breathable the base layer, the better suited it is for hot summers because it allows more airflow in while moving moisture out. 

Should you wear a base layer in summer?

Whether or not base layers are effective in warm weather is debated. Some cyclists think base layers are beneficial in all seasons, as long as you wear the right base layer for the temperature. They acknowledge that sweat keeps you cool but believe a base layer assists in the transport and evaporation of sweat by wicking the moisture off of the skin and onto the outside of the material to evaporate. 

On the other hand, many cyclists say that if your jersey is designed for moisture-wicking, then there’s no need for a base layer. And many jerseys today, like the Hincapie Momentum jersey, are excellent at controlling moisture. According to one study, skin evaporates sweat faster without any barrier inhibiting evaporation. Any additional material between the skin and the air slows evaporation. However, this study was inconclusive about what impact clothes with evaporative properties have on evaporation. 

If you’re not sure whether or not to use a base layer when it’s warm outside, test it out. Additional comfort is a primary reason for wearing a base layer, so if wearing one in summer isn’t comfortable, then it’s better to go without. But keep in mind that there are many other benefits to a base layer in addition to keeping you warm or cool. 

Benefits of wearing a base layer for all seasons

  • Regulates your core temperature
  • Prevents chafing against bibs or jersey 
  • Prevents your chest from shining through in a light or white jersey 
  • Allows you to unzip your jersey to cool down without exposing your chest
  • Keeps you drier when cycling in the rain
  • Creates a soft barrier between you and your jersey for additional comfort
  • Decreases your risk of road rash from a fall by giving you a protective layer

Long-sleeve vs. short-sleeve vs. sleeveless base layers

It’s important to choose the right type of base layer for the climate and your comfort. The appropriate sleeve length varies according to the temperature, time of day, and personal preference. 

Long-sleeve base layers are best for cold-weather or chilly mornings. In winter, you need to warm up more than just your core–you’ll need to cover your arms and possibly your neck too, for adequate insulation. When trying on a long-sleeve base layer, make sure that the shirt tail and sleeves don’t leave any gaps between your gloves and your wrist or at your waistline where air can creep in. 

Arm warmers are an alternative to long-sleeve base layers, but they won’t help insulate your core. However, you may want to add arm warmers with a short-sleeve base layer if you live in a climate with very few cold days. The short-sleeve base layer will help maintain your core temperature, and you can remove the arm warmers once you’ve warmed up. 

Short-sleeve base layers are great for all seasons. They’re a summer cycling staple, and merino wool short-sleeve base layers are also perfect for mild winters. They also work well in fall or spring or on brisk mornings. 

Sleeveless base layers are an alternative to short-sleeve base layers, and many cyclists find sleeveless more comfortable. Without sleeves, there’s no potential for restricted movement or bunching at the shoulders. Sleeveless base layers are great for tight-fitting jerseys when you still want the benefits of a base layer but want your jersey sleeves to be snug against your arms.

The best materials for cycling base layers

  • Merino wool is a popular material among cyclists. It’s an excellent insulator but not as good at wicking moisture as synthetic materials, so it’s most frequently used for winter riding when you don’t sweat as much but need to stay warm. This material keeps you comfortable in the cold without adding any bulk. It’s naturally odorless and quick-drying, which makes it a great choice for arriving dry and still smelling fresh after commuting. Its bacteria-repelling properties are also beneficial on long cycling excursions. Merino wool is a renewable fiber that’s completely biodegradable. 
  • Synthetic materials are appreciated for their comfortable stretch, tight fit, and excellent sweat management. These materials include Lycra, polyester, and nylon. They’re often used for aerodynamic, performance cycling clothes because of the smooth and tight fit they provide. Synthetic materials are highly breathable but not as warm as merino wool. 
  • A blend of both merino wool and synthetic materials combines the warmth and odor-inhibiting qualities of merino wool with the stretch and excellent wicking and snug fit of the synthetic materials. Cycling clothes made from a blend of natural and synthetic fibers are versatile and provide comfort in all seasons. 

How to wear a cycling base layer

A base layer is the foundation of your cycling kit. You wear a base layer under your bib shorts or bib tights, under your cycling jersey, and in winter, it’s topped off with a cycling jacket. A base layer is most effective at wicking moisture and insulating when it’s in close contact with your skin, which is why it should go beneath all other layers in your kit.

How should a cycling base layer fit?

A cycling base layer is supposed to have a snug fit to wick moisture well, but it shouldn’t be so tight that it bunches or inhibits movement. Seams should also feel smooth and sit flat against your skin, so they don’t rub and cause sores. The hemline of a base layer should be long so that you’re fully covered in a riding position, and so you don’t feel wafts of cold air up your shirt in winter. Ragland sleeves that extend from the collarbone to the armpit are best for base layers since there are no seams over the shoulder.

5 of the best cycling base layers

Best sleeveless baselayer: Hincapie Power Dry Cooling Mesh Base Layer

Cost: $30

Power Dry Cooling Mesh Sleeveless Base layer

This Hincapie base layer is designed to take on sweat with its super breathable, fast-drying mesh. It’s made from one of our most breathable, moisture-wicking materials with PolarTec Delta technology to keep you cool. 

Best base layer for winter cycling: Rapha Pro Team Thermal Base Layer 

Cost: $100

The Rapha Thermal Base Layer is perfect for performing your best in brutal winter conditions. It’s designed with polyester in heavier weights around the most critical areas, so that warmth doesn’t come at the cost of moisture-wicking when you’re racing or training hard. The turtleneck can extend above the nose and mouth when the freezing wind starts to burn. 

Best baselayer for summer cycling: Hincapie Power Dry Short Sleeve Base Layer

Cost: $40

Power Dry Short Sleeve Base layer

The Hincapie Power Dry Short Sleeve base layer is designed to move moisture fast for optimal performance in hot weather. The PolarTec Power Dry technology protects your body from overheating, and its odor-resistant material keeps the sweat and stench away. 

Best Windproof Base Layer: Gore Windstopper Base Layer Thermo Long Sleeve Shirt 

Cost: $100

This base layer is designed with Gore’s Gortex Infinium material with microscopic pores that let moisture out but won’t let the wind in. The base layer has an armor of wind-stopping inserts that defends against blustery weather. 

Best merino cycling base layer: Hincapie PowerCore Merino Long Sleeve Base Layer

Cost: $80

PowerCore Merino Long Sleeve Base layer

This Hincapie base layer is made from porous merino wool that is excellent at absorbing and evaporating sweat while retaining warmth. It’s constructed with Flatlock stitching so you don’t give seams a second thought while riding. The long cut leaves none of your torso exposed to the cold. This merino base layer is also available with short sleeves.

Once you’ve found a great base layer, choose from our other buying guides and start layering up with other cycling kit essentials.

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