Pearl Izumi Barrier hat £16.99 + Castelli Viva Thermo Skully hat £20

We’ll assume that you wear a helmet when mountain biking so you’ll know just how chilly all those vents can make your head, encouraging frozen air to pass over your head.

This is where winter hats, or skull caps as they’re often called, serve a very useful purpose. As helmets need to be of a good fit for safety reasons, your options for keeping your head warm are a little limited. Thin hats (like the pair pictured above)  fit snugly over your head and ears but importantly don’t obstruct the helmet from fitting correctly, leaving your head toasty warm.

When it comes to surviving the winter, they’re an indispensable investment. You won’t look back. As with everything in cycling, there’s a huge choice out there, so we’ve narrowed it down for you and have looked at two offerings from Pearl Izumi and Castelli.

With its professional road racing connections, Castelli make some mighty fine clothing that shouldn’t be ignored by mountain bikers, with proven performance in the tough arena of road racing. The Viva Thermo Skully hat is a good case in point. It’s made from a thin and very stretchy Thermoflex material with a ‘raw edge’ design, a large band that sits over the ears and limited stitching. This all leads to it being extremely comfortable. Granted, you do feel like a swimmer pulling on a swimming cap wearing it, but once on and your helmet clipped into place, it’s like it’s not even there.

Being based in Boulder, Colorado means Pearl Izumi know the meaning of cold winters better than most, and the Barrier hat is just one of a large range of head warmers on offer. It’s made from the company’s own Barrier windproof fabric, a  100% polyester construction, with a single layer design keeping the bulk to a minimum, but double layers in a band over the ears. Like the Castelli, it fits well with enough stretch to cover over the ears without any tightness.

Castelli claim their Skully is good for temperatures down to 5 °C and while it hasn’t really been that cold in the South East just yet, it’s been good for temperatures that fall firmly into single figures. The Pearl Izumi Barrier works well in a similar temperature range, but just has the edge of warmth in our tests, with the double layer of material over the ears offering a noticeable increase in protection in this area.

The fit and comfort of the Castelli is a measure above the Pearl Izumi. Both use a ‘one size fits all’ approach, the Castelli a little more generous in length ensuring the ears were well covered, the Pearl Izumi could do with being just a bit longer.

Verdict

Both are excellent performers in single digit temperatures, with comfort beneath a mountain bike lid exceptional. With its lower price tag, understated styling and warmth, the Pearl Izumi Barrier hat just nudges it for us.

Castelli – www.saddleback.co.uk

Pearl Izumi – www.madison.co.uk