Mick's Tips - Water-proof Jackets

Following on from the last contentious episode on Lycra shorts, for this week’s T.o.t.W I will mostly be addressing the matter of performance outer garments.

I think we have concluded that you don't need multi-panel high performance garments to pootle to the shops, and that you'd probably not embark on a 200k road race wearing cords and a duffel coat. It's all about using the right gear for the job. One woman’s frenetic six mile sprint to work is unlike the next man's half arsed trundle to the dole office. Horses for courses and all that.

Performance fabrics become more relevant as speed, distance and effort increases. They are designed to mimic, even become an extension of, the skin – by enabling us to moderate temperature and control moisture. Cycling apparel has evolved in accordance with the principles of layering. That is to say, a base layer designed to be worn next to the skin, an outer layer of water-proof and breathable material separated with an insulating layer or layers according to need. The key performance feature of all cycling garments is their ability to control moisture generated by sweating. To do this each layer is designed to lift moisture from its inside surface and deliver it to its exterior surface.

The key feature of the outer weather-proof garment, or ‘shell’, is its ability to prevent rain water getting in whilst allowing sweat to escape. They are made from or incorporate a membrane composed of tiny holes which allows small water moisture molecules to pass outwards but not large water drops to get in. Non- breathable garments can’t let water vapour escape, so it condenses into liquid on the inside surface and dribbles out of your sleeves. Ew. Also be aware that outer garments can only work to their optimum capacity if you wear performance fabrics under them. Cotton garments certainly absorb moisture, but they don’t let go of it very well. They don’t deliver it to the outer shell. If you are still getting sweaty inside a £200 jacket this is probably why. Same if you dont wear anything under a breathable jacket. if the membrane sits directly on your skin moisture condenses into water. You need a boundary layer - it's why many jackets have mesh liners.

The challenge for manufacturers is to balance durability (fabric cost), fit (which requires tailoring), features (such as pit vents, pockets, adjustable cuffs etc), fabric performance (its ability to do its job) against cost. Features cost money. As with most things, the more you pay the more you get.

It’s worth investing in your outer shell. Treat it right and you’ll get years of use out of a good one.

Look out for: Taped seams. Without wishing to state the bleedin’ obvious, stitches make holes, and holes let in water. You can have all the fancy waterproof/breathable materials but if you don’t tape the seams after they’ve been stitched you might as well be wearing a bin bag. Taping requires assembly time in the factory. It costs more, but you’d be daft not to buy a jacket with taped seams.

Tailoring, or the ‘cut’ should suit your riding position. A racing bikes’ position requires a very different cut to a ‘sit-up and beg’ come to Jesus bike.

Vents: There are occasions when the generation of sweat exceeds even the most breathable outer shell’s abilities to disperse it. Warm, wet days. Pit vents allow you blow air through the jacket without letting in water.

Adjustable cuffs, likewise. A looser cuff which is adjustable via Velcro is a bit more expensive to manufacturer than an elasticated cuff but it allows you to control air flow through the sleeves – and makes it easier to control your temp.

To establish if a cycling jacket is big enough for you, wear the largest jumper/ fleece that you are likely to wear under it, bend slightly forward to mimic your position on the bike and then stick your arms straight out in front of you. If it rides up exposing your wrists it’s too small.