Base layers are the perhaps the most functional pieces of your entire cycling wardrobe. Choosing the right base layer means being able to wear short sleeve summer jerseys from smokin’ hot temperatures down to 40 degrees or less. Base layers mean that a light long sleeve jersey can be just the ticket for a ride starting near freezing and warming up to near 60. Layering also allows a jacket to take you from right around freezing to as cold as you want to go.
The first word of advice for all base layers is to get them snug. Form-fitting is key. Base layers not only help regulate your body’s temperature, but they also carry perspiration away from your skin. The base layer can do neither if it is loose-fitting and there are pockets of air between it and your skin. I’ve found that snug for me is quite different from brand to brand, and even sometimes among various layers from the same company. For example, with Craft, I need medium in the sleeveless base layers, but large in their short sleeve mid-weight base layer and in their jackets/jerseys. For all things Castelli, I wear size XL. With Omniwool, I’m size L.
Though I am a big proponent of supporting your LBS, my local shop doesn’t always have a huge selection of winter gear, especially when it comes to base layers. For online purchases, I highly recommend that you make sure you’re dealing with a company that will not hassle you or charge you for returns/exchanges, especially considering the differences in fit mentioned previously. I’ve had good dealings with Colorado Cyclist in this regard. Speaking with their sales representative on the phone while debating jackets and sizes, he even recommended that he send me two sizes of two different jackets I was considering, and I could send the three back once I decided the one I wanted. Also, Competitive Cyclist has a 60 day no questions asked (NQA) return policy which I’ve been thankful for several times.
Another general pointer when riding on the roads in the winter is that it’s not as much the temperature that makes you cold as it is both the ambient wind and the air flowing across you as you ride. Your body is naturally warming as you exercise, so if you can block at least some of the wind, you’ve gone a long way towards staying comfortable.
Though these articles are to concentrate on cold weather gear, I must briefly mention my summer base layers as they do sometimes see use on cool/cold rides. I absolutely love Craft’s summer sleeveless base layers. I have three different weight summer base layers from their ProCool range. The Superlights, the lightest weight, are usually folded away until summer returns. However, I’ve found that the ProCool and even the ProCool mesh can extend the temperature range of a long sleeve base layer by 5 degrees or so by providing additional insulation to your chest/core area.
Moving on to long sleeve base layers, I find that my favorite and most versatile are the light to mid-weight options. After some trial-and-error (money wasted), I now make sure that they all pass my “see-through” test. If I hold my hand against the inside of the fabric and it is thin enough that I can see my hand through it, then the base layer is too thin or the fabric weave is not tight enough. Remember, we’re trying to keep the wind off our skin for cold weather rides. It’s been my experience that a lot of the natural fabric, i.e. wool, base layers are too thin and don’t do a very good job of providing protection from the wind. My perfect cool to cold weather base layer is the Castelli AirCo (pictured, right) base layer. This base layer passes my “see-through” test, fits quite snug yet seems to disappear when wearing it, and does a great job moving sweat from my skin. I still see some of these online, but it looks like Castelli has replaced it with the Iride for this season. I prefer to pair the Castelli with a short sleeve jersey for 45 to 55 degree rides, and add a sleeveless base layer to this combination for 40 to 45 degrees, wear it under a long sleeve jersey or add arm warmers to the AirCo/sleeveless set-up for 35 to 45 degrees, and wear it under Windstopper jerseys and jackets for temperatures less than 35.
A big advantage to keeping the base layer as light as possible is that it’s easier to regulate your temperature as the weather warms during a ride. By unzipping your jersey or jacket, you can quite effectively cool yourself should the temperature rise. However, if you’ve gone with a thick base layer and light outer layer, you won’t be able to cool as well by simply unzipping.
Several base layers are also offering the option of Windstopper or some sort of wind block material. Though I did stress the importance of blocking the wind on winter rides, it is my opinion that this is not the way to do it. It might seem like a nice option in some cases, but remember that the breathability of the fabric is highly compromised due to the wind block. Therefore, I much prefer to limit wind block to my outer layers.
So, in summary, it’s been my experience that for all-around versatility, finding a base layer that is well-constructed, form-fitting without being uncomfortable, does a good job of cutting down the wind, and still wicks moisture away from your skin, provides the most bang for your buck. A good, light, long-sleeve base layer can be used from early fall to late spring when properly paired with outer layers.
As I said in the introduction for these discussions, I haven’t tried even a small fraction of the base layers that are out there. Feel free to comment on what works well for you or even what didn’t so we can all help each other make better informed purchases. Hopefully we can also help each other stay off the rollers/trainer as much as possible this winter.