Writing for the web
So, to get straight to the point, what do base layers actually do?
Well, base layers are designed to transfer the sweat away from the surface of your skin to the outer layer of the garment where it can quickly evaporate away. This process is called ‘wicking’ and its aim is to keep you feeling dry, comfortable, and chill-free.
Base layers are made from either blends of synthetic materials such as polyester/elastane/polypropylene or natural Merino wool.
Synthetic base layers work by drawing moisture away from your skin through micro tubes in the material's fibres (capillary action) whilst Merino wool garments rely on the natural wicking properties of the wool fibre itself (hydrophilic fibres).
For the best wicking results, a base layer needs to be a nice snug fit next to your skin. This is usually quite easy to achieve as both Merino wool and synthetic blends have great stretchy qualities. It’s also worth remembering that if a baselayer is too loose, you will lose some of the wicking properties due to the inner surface not being close enough to the surface of your skin.
Well, to get the most out of a baselayer, you really need to get season specific ...
Summer base layers are made from the lightest of synthetic materials. Mostly sleeveless with low cut necklines, summer base layers are designed to be skintight so they can be worn under the closest fitting of cycling jerseys. However, there is a certain amount of disagreement within the ranks when it comes to the effectiveness of summer base layers when temperatures exceed 30° - but if you live in the UK - probably something you won’t have to worry about too much.
A Funkier Polyamide and Elastane meshed sleeveless summer baselayer – warm weather comfort control
Spring/autumn base layers are heavier than the superlight summer layers as they need to offer a certain amount of thermal insulation. Made from either synthetics or light merino wool, spring/autumn base layers have mid-height collars and half sleeves to help keep the chill at bay. On cooler days, most riders use mid-weight base layers in conjunction with arm warmers for optimum comfort control.
A dhb mid-weight synthetic mix baselayer with half sleeves – for those cooler days
Winter base layers work in much the same way as lighter garments but have the added task of acting as a thermal layer. This means they need to be a slightly looser fit than standard wicking garments to allow a layer of insulating air to be trapped next to the skin. Made from Merino wool or heavier synthetics, thermal base layers have long sleeves to help keep the blood circulating in your forearms, high collars and longer hems.
A full sleeved Castelli Merino wool baselayer – stay toasty and dry, thermal insulation and wicking for winter riding
If you ride all year round, you would certainly benefit from having a set of season specific base layers. But that said, you can get away with using a mid-weight base layer for most occasions. You will need to make up for the heat loss on colder days with heavier mid and top layers, but the wicking will still keep you dry and comfortable. You may also find a that using a mid-weight on hot days can be a tad overkill.
And some other considerations...
In the fight against unpleasant odours, Merino wool definitely has the upper hand over synthetics. This is due to the fact that Merino wool fibres have very smooth outer surfaces that deny bacteria good breeding toeholds. Synthetic fibres on the other hand, even though treated with various anti-bacterial formulas are rougher than wool, meaning life is a tad easier for these ponging bacterial life forms.
So, whilst Merino wool certainly works better at keeping unwanted whiffs at bay, it’s way more delicate than synthetic materials when it comes to laundry day. This means careful laundering and drying are a must to keep them in tip-top condition. With a synthetic baselayer, you can simply bung it in the washing machine with the rest of your cycling kit and completely forget all about it.
Synthetics are generally quite a bit cheaper than Merino wool, hence a lot more popular. But, if you have the cash to splash for winter kit, Merino is generally seen as the warmer option.
Posted by DL