Years of racing and training in the wet weather of the Pacific Northwest taught me the key points to look for. Which one is right for you? Let my experience be your guide.
Waterproof or water resistant?
Is the jacket waterproof or only water resistant? True waterproof jackets keep you dry, even in the heaviest of rain. If the ticket says waterproof, the seams on the inside of the garment should be “taped” or “sealed”. You’ll see a visible closed layer over the seams that prevents water from getting in the needle holes where the fabrics were sewn together.
The zipper has to keep the water out too, but don’t expect to find 100% waterproof zippers in a rain jacket. They are typically made of rubber and have a completely different look to traditional ones. You find them more in wetsuits.
Rain jacket zippers are effective, but water resistant only. The manufacturer does this by ultrasonically bonding or seam-sealing it into the garment. It should have a water repelling polyurethane coating on the outside and a second water repellent treatment on the inside to prevent water from penetrating. The devil is in the details, so read the garment tag.
Construction
Waterproof jackets with a three-layer construction are the most breathable and comfortable to wear. An ultra-thin waterproof membrane is sandwiched between the face and lining fabrics. It’s loaded with microscopic pores several times smaller than a water droplet. This difference in size allows body heat to escape and reduces the buildup of interior moisture while keeping the rain out. The face fabric does its part to buffer the rain and wind too.
Just how waterproof a garment is boils down to a number measured in millimetres of “water column” that falls between 5,000 to 30,000. The larger the number, the greater the protection from water. A 5k mm jacket would be okay in a drizzle, but not much more. 6-10k mm garments shield against light rainfall. You’ll need more protection as the intensity of the precipitation grows. 16k to 20k mm+ provide the maximum protection and remain waterproof under heavy rainfall.
Breathability
Today’s rain jackets are a far cry from the plastic-like ones you see the pros wearing in vintage cycling footage. Sure, it kept the rain off, but they still got soaked in their own sweat inside because it didn’t breathe. The amount of water vapour, aka sweat, the garment fabric releases determines how breathable it is.
Measurement values are in “g/m2/24hrs” following a MVT (Moisture Vapour Transmission Test). The result represents the quantity of water, in weight, that passes through a square metre of any fabric over 24 hours. The higher the number, the greater the breathability. 10k-20k is an industry standard and does an acceptable job of evacuating heat and moisture. 20k-30k figures prevent that damp and clammy feeling inside, unless you’re really working hard. And 30k+ means maximum breathability without sacrificing waterproofness. If you can’t find 30k+ ratings, some say the difference between it and 20-30k is imperceptible. Something to keep in mind.
The “Upright” and “Inverted Cup Test” are like the MVT when measuring breathability. You may see references to these words on garment hang tags. The brand Gore-Tex uses a RET (Resistance of Evaporation of a Textile) rating presented with a “< or >” symbol in front of a number, i.e. RET <9. Here, the lower the number, the better, so don’t confuse the values.
Tail and hood
If you don’t ride with a mudguard to prevent the splash coming off the rear wheel, get a jacket with a long tail. This will spare you the miserable experience of a waterlogged chamois. In fact, choose a rain jacket with a long tail, anyway. You can never be too careful and you can use it on any bike.
Be wary of tails that seem long enough in a picture or on the hanger. Looks are deceiving. You won’t know for sure until you’re in your riding clothes on your bike, and have the jacket on. Testing it on a hometrainer is best. Does the tail sufficiently cover your rear when in the riding position? As you pedal, does the jacket ride up around the waist? Don’t remove the tags and wear it outside until you’ve answered these questions.
Do you need a hood? That’s up to your preference and where you ride. If you aren’t sure, opt for a removable one and decide later. Choose models that fit over your helmet without compromising on visibility. A fully adjustable hood with a peak directs rain away from your face.
Fit and packability
Rain jackets come in different cuts. One that fits well is important for functionality and comfort. A quality rain jacket keeps you dry and warm by also protecting you from the wind. You might have to go up in size if you wear it over bulkier layers in the spring, fall and winter. If it’s too tight, it could pull in the shoulders or ride up around the waist. One that flaps around annoyingly like a flag in the wind isn’t desirable either. The noise alone will drive you nuts.
Carrying a rain jacket that packs easily in a rear pocket is practical. But true packability and waterproofness don’t always go hand in hand. You may have to sacrifice one characteristic over another. A highly waterproof jacket that protects from rain and cold probably won’t roll up into the size you think either. If the rain gets bad, you can take cover under some dense trees or in a coffee shop. You wanted a coffee about now, anyway.
Visibility
Why do people wear black rain jackets? Can someone explain it to me? I get that black shows less road crud, etc. But if the weather is already miserable, and you’re out on the road, don’t you want visibility on your side? Buy your new rain jacket in a highly visible colour, please.
Reflective details on the jacket in low light conditions also improve your chances of being seen on the road. And I don’t mean a tiny tab of reflective material sewn into a seam on the side. For your safety, favour large reflective details across the chest, back and shoulders.
Final considerations
A proper rain jacket is an investment. And to protect it, you need to follow the garment’s care recommendations. The more you wash it, the faster the waterproof coating strips away. Between washes, let it air dry before giving it a good shake to remove debris. However, occasional washing is necessary to keep the membrane pores free of sweat and dirt.
When the time comes, treat it with a re-proofing product available post sale. If the jacket gets ripped or torn, contact the manufacturer. Some repair them for free or for a minimal charge. If not, waterproof patches are readily available and more cost efficient than a new jacket.
In your quest, prioritise the features we covered here, but don’t forget a tall collar, underarm zippers, rear vents, draw strings, fitted cuffs, and waterproof pockets for personal items when considering a garment’s functionality and breathability. Now you’re ready to find yours. Enjoy your ride, rain or shine.
