Breathability
Breathability
As we mentioned on the previous page, breathability is the attribute that allows jackets that can sometimes look like plastic bags to not feel like you’re wearing Tesco’s finest.
Now pretty much all water resistant jackets promise breathability, but the difference between one that does it well and one that doesn’t perform is marked. Of course, it’s difficult to judge the breathability of a jacket until you’ve had the chance to ride it in… by which time you’ve bought it, but, generally speaking, those fabrics which cost a little more to produce will offer more breathability than budget options. Still, regardless of how breathable a material is touted by the jacket’s manufacturer, you may also want to look at other features like mesh or venting. In our experience, Sportful’s range of HotPack jackets offer impressive breathability, and have an additional vent to keep things cool, while offering water resistance in a compact package.
Under the arms is the ideal position for vents, because the arms themselves will provide cover from rain trying to work its way in. Similarly, zipped vents give a nice optional extra for days when you’re working hard but still need the protection of an outer shell. Basic zips are far from waterproof, but are far better than an open vent. Similarly, overlapped vents are a popular feature as well. The most common being a vent across the middle of the back where the top piece of material drops down over the vent to stop rain getting in. It’s another basic design but, again, is rather effective as allowing a little air in to cool you down and allow heat to escape.
The main thing to know about breathability is that the reason a rider gets sweaty inside a jacket is that the rate they’re generating heat is greater than the jacket’s ability to remove that heat build-up and moisture. So the most breathable jackets are the ones that are best at transferring moisture from the inside to the outside. There are two main ways this happens. The first is by using a microporous hydrophobic material. That’s basically a fancy way of saying that the material has tiny pores which allow moisture vapour through one way, but don’t allow water through the other way due to the difference in the size of the molecules. That’s the trick with a lightweight jacket, striking the balance between allowing moisture to escape while still offering a good level of water resistance. The second way is with a hydrophilic coating on the outside of the fabric. In other words, it attracts water and this will draw the water through the material.