Warm skullcap with a windproof band that keeps the cold air off your forehead and ears
Castelli WS Skully
8 10

This skullcap comes with a windproof band around the forehead and temples which keeps the cold air out when the temperature gets really low.

The band is made from Gore's Windstopper X-Free fabric which is a stretchy, fleece-backed, softshell fabric. It protects your forehead and the tops of your ears which, in my experience, are the areas that suffer most when the mercury is low, completely shutting out the cold air.

The other areas of the cap are made from what Castelli call Warmer fabric which is also fleecy and stretchy, but it isn't windproof. In that way, the WS Scully follows similar principles to many cycle jacket designs: windproof for the most exposed panels, more breathability for the less exposed sections. That's not to say that the Windstopper fabric isn't breathable; it is, but it's not as breathable as the Warmer fabric.

Unlike most skullcaps, this one reaches down to cover the back of your neck so there's no gap down to the top of your jersey or jacket. It comes in just one size but the amount of stretch you get here means it'll fit just about everyone, and it'll sit comfortably underneath a helmet as long as you have enough adjustability to slacken off the fit.

Out on the roads, this has kept my head warm on even the coldest mornings. I've been out in freezing temperatures wearing this and I've felt fine with this on, even on fast descents. I've used skullcaps before that are windproof throughout and I've found them too sweaty. By just having just a band of Windstopper fabric, this is much more comfortable.

Castelli reckon this is suitable for riding in 5-10°C. I usually agree with the temperature ranges they give, but not here. I'm just back from a steady ride in 6°C and I had to take the WS Skully off after 15mins because I was too warm... and I'm a bloke who feels (and loves to moan about) the cold. I'd say it's more suitable for temperatures up to 5°C.


Warm skullcap with a windproof band that keeps the cold air off your forehead and ears

road.cc test report

Make and model: Castelli WS Skully

Size tested: Black, one size

Tell us what the product is for, and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about it?

Castelli say, "For extreme cold conditions, the Windstopper® band covers the front of the cap and the top of the ears, while the bottom of the ears are covered in our Warmer fabric so your hearing is not impaired. It extends farther down the neck for extra warmth.

- Windstopper® X-free on front for wind protection

- Warmer fleece fabric feels soft, wicks moisture, and feels comfortable under your helmet

- Cut long on the back for perfect closure with jacket

- Fits comfortably under a helmet and extends over the ears"

That all sounds reasonable enough. The only thing that I'd take issue with is the temperature range of 5-10°C. I'd use it only when the temperature is lower than that.

Tell us some more about the technical aspects of the product?

The windproof band is made from Gore's Windstopper X-Free fabric which is, according to Gore, "The first Windstopper fabric that offers 4-way stretch in a 300 gram fleece-backed winter weight."

It feels to me a lot like the Windstopper X-Lite Plus fabric that Castelli use for their Gabba WS Rain Jerssey.

Rate the product for quality of construction:

It's neatly done and the seams didn't bother me when I wore this under a helmet.

Rate the product for performance:
Rate the product for durability:

Should last ages. It goes through the washing machine with the rest of your cycling clothes fine.

Rate the product for comfort, if applicable:
Rate the product for value:

You can get cheaper skullcaps with windproof panels, but this one is the best I've used.

Tell us how the product performed overall when used for its designed purpose

It performs really well, making very cold rides much more enjoyable.

Tell us what you particularly liked about the product

The windproof panel is exactly where you need it, and the extension down your neck is welcome too.

Did you enjoy using the product? Yes

Would you consider buying the product? Yes

Would you recommend the product to a friend? Yes

Overall rating: 8/10

About the tester

Age: 41  Height: 190cm  Weight: 75kg

I usually ride:   My best bike is:

I've been riding for: Over 20 years  I ride: Most days  I would class myself as: Expert

I regularly do the following types of riding: time trialling, commuting, club rides, sportives, general fitness riding,


Mat has worked for loads of bike magazines over 20+ years, and been editor of 220 Triathlon and Cycling Plus. He's been road.cc technical editor for eight years, testing bikes, fettling the latest kit, and trying out the most up-to-the-minute clothing. We send him off around the world to get all the news from launches and shows too. He has won his category in Ironman UK 70.3 and finished on the podium in both marathons he has run. Mat is a Cambridge graduate who did a post-grad in magazine journalism, and he is a past winner of the Cycling Media Award for Specialist Online Writer.


Dr_Lex [469 posts] 6 years ago

Available in white? Quite fancy the early cosmonaut look.