b'Twin Aerofit Wind Undershirt

The b'Twin LS Aerofit Wind base layer from Decathlon is part of the French sports superstore chain's extensive array of cycling kit which covers everything from socks through to full bikes. The brand is growing year on year and on the whole value for money is the main drive.

At £34.99 the LS Aerofit Wind is positioned near the top of a range of baselayers that starts at just £5.99. The 'Wind' part of the name comes from the polypropylene front panel intended to keep your core warm against cold winds. The membrane runs from the chest down to the abs, exactly where you're going to take the breeze when in a crouched road position.

The rest of it is made up of a 97% Nylon/3% Lycra mix knitted at varying weights to create mesh style sections for breathability. The widest mesh is under the arm pits for the greatest heat transfer while the back panel carries a tighter mesh section down the centre and either side, ideal for rucksack/hydration pack users.

Around the waist the Aerofit Wind is contoured inwards to create a close fit which is what you want as a baselayer becomes more effective the closer to the skin that it is. The material doesn't quite offer a level of compression for a full second skin fit which as it's called Aerofit I'm guessing it is intended to have.

The hem, neck and cuffs are knitted, creating grip without the use of silicone or elastic grippers, which I find much more comfortable; it stayed in place no matter how much I changed position.

The mild winter we're having so far highlights the Aerofit Wind's intended temperature is around the freezing mark if you wear it under a softshell or windproof jacket. It can get pretty warm as your effort increases. If you're an early season racer needing to display your club/team colours though, it's perfect under a standard jersey up to around 10 degrees.

When riding on the odd cold day, -5°C I think was the lowest, the Aerofit Wind finds its sweetspot especially when you add in the windchill factor. Your chest and lungs benefit the most from the extra insulation. Breathability isn't quite as good as some merino options but if it does get wet from perspiration you do at least stay warm.

On the whole the Aerofit Wind offers a good fit with its dropped tail and the performance is impressive as long as you give your layering options some consideration before you set off. The material is soft against the skin with no itching or irritation from the seams which themselves look well constructed.

Black is the only option although colour choice isn't a major worry for most when it comes to baselayers and there is a wide range of sizes from S-XXL. With b'Twin backing all of this up with a two-year guarantee makes value for money look pretty impressive against other similar products on the market.

Verdict

Comfortable, well-fitting, base layer at its best in sub-zero conditions.