Castelli Flanders High Collar Winter Cycling Base Layer Review: Tried and Tested

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Review score


Castelli Flanders is definitely one of the warmest winter cycling base layers out there. The fabric quality, comfort, fit, wicking properties, and even an in-built neck warmer make this base layer one of the best on the market. Price is the only downside for which I deducted one point.

product and testing details:

I personally find base layers to be one of the most critical pieces of gear when it comes to cycling clothing. This is because base layers are designed to regulate the rider’s temperature through moisture management. As a result, base layers make cycling more comfortable & enjoyable.


I own a few base layers for different weather conditions and seasons of the year, and in this review, take a close look at Castelli’s Flanders Long Sleeve High Collar winter cycling base layer.


In my opinion, it is the warmest and the highest quality base layer in my possession.


Castelli Flanders winter base layer was designed for the coldest winter days. The recommended temperature range is actually 18°-43°F / -8°-6°C. Unfortunately, I did not have a chance to test it in such extreme conditions as 18°F / -8°C since it does not get as cold where I live.


This is why the lowest temperature I tested it in was around 32°F / 0°C, and this base layer was more than capable of keeping me warm and comfortable. So if your winters are harsh and you need the extra warmth, then Castelli Flanders is the base layer you need.


On the flip side, it can be too warm when temperatures are above 43°F / 6°C, so you might need to adjust your clothing accordingly. Check out below how I am using this base layer and tackling this issue.


Scoring Castelli Flanders a 10/10 for warmth.

Size & Fit

There is often a lot of confusion about Castelli’s sizing because sizes differ from one brand to another. I often find comments online about going a size up when purchasing Castelli products. However, I recommend following the official size chart to find your size.


For example, I usually wear a size S, and the Flanders base layer size S fits me perfectly. I have no complaints about the size and fit. In my case, the base layer is snug-fitting, sits perfectly against the skin, and does not cause any discomfort across the shoulders, chest, or sleeves.


This is why scoring it a strong 10/10 for the size & fit.


Like with warmth, Castelli Flanders is the most comfortable base layer I own, and I feel good when wearing it. It feels soft against my skin and does not cause any discomfort even on long rides. The fabric is fantastic, and I am really happy with it.


This is why scoring Castelli Flanders a 10/10 for comfort.

Moisture Management & Wicking Properties

A winter cycling base layer must have good moisture management and wicking properties. As I mentioned at the beginning of this review, managing sweat & moisture while cycling is key to feeling comfortable and warm.


Castelli Flanders winter base layer excels in this area, and I found several reasons for this:

  1. The fit is close to the skin, so the sweat is instantly pushed into the fabric.
  2. The fabric is thinner at the armpits, which is done on purpose so the sweat can evaporate easier.
  3. The fabric has technical quick-drying properties, so it manages to dry very quickly and evaporate excess moisture even if you sweat a lot.

However, keep in mind that you need to think about your clothing when cycling in winter. It is important not to overdress because you can easily overheat.


Again, giving it a perfect score of 10/10 for the wicking properties and moisture management. 

Neck Warmer

Castelli Flanders comes with a built-in neck warmer which is great on those coldest days when you can feel the cold against your face. You can just pull it up and it will cover your neck and lower part of the face. Made of the same fabric as the base layer, it feels great against the skin, does not cause any discomfort, and adds to the overall warmth.


I also own 2 neck warmers, but now don’t use them when wearing this base layer. I find the in-built neck warmer a really nice feature.

How do I use Castelli Flanders winter cycling base layer?

The right clothing and proper layering are vital to staying warm and comfortable in winter. Knowing how to dress up for winter comes with experience and errors. I personally consider a few factors like the rain, wind, temperature, intensity level, and how well my body copes with the cold.


Here are 3 examples of how I use Castelli Flanders base layer in winter:

  1. If the temperature outside is around freezing, in addition to Castelli Flanders, I add a long-sleeve cycling jersey and C5 Gore-tex Shakedry Viz Jacket (full review here). If needed, I can unzip the jacket or even store it in the back jersey pocket.
  2. If the temperature outside is from 43°F / 6°C to about 50°F / 10°C then I use the same jersey, Castelli Flanders base layer and pack the C5 Gore-tex Shakedry Viz Jacket in my back pocket. I can easily take it out if it starts raining or feels cold at a coffee stop.
  3. If the temperature is above 50°F / 10°C, I use a different short-sleeve base layer with the same jersey and sometimes take C5 Gore-tex Shakedry Viz Jacket in the back pocket just in case.

I hope these examples give you some ideas on using Castelli Flanders winter cycling base layer depending on the weather outside.


In summary, these are the things I like about Castelli Flanders Long Sleeve winter cycling base layer:


It is super warm and keeps you comfortable even on the coldest days.


The fabric feels great against the skin and does not cause any discomfort even during long rides.

Wicking properties

The fabric is very quick-drying and manages moisture really well.

Incorporated neck warmer

The built-in neck warmer is a great feature, especially on cold days when you want extra face protection.


The fabric looks durable and should last many seasons with good care.


What I did not like about Castelli Flanders Long Sleeve winter cycling base layer:


It is pretty expensive, and not everyone may be willing to pay for a base layer the price of a good cycling jersey or even a jacket.

Final Verdict

I would recommend Castelli Flanders to anyone looking for one of the warmest base layers out there and can afford the price tag. The fabric quality is outstanding, and this base layer excelled at every category I tested it against. You also get a built-in neck warmer, which I find to be a very nice feature.


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