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Review: Kalas RainMem affordable foul weather kit keeps you warm & dry

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It’s cold & wet outside for us riding these days. And that means the need to bundle up. For me it seems the hardest weather to dress for is just a few degrees above freezing, where the roads & trails seem to be perpetually wet. That’s when insulating, highly water-resistant gear like the Kalas RainMem kit really shines.

Kalas RainMem waterproof bib shorts, jersey & warmers

Czech-made Kalas Sportswear has been around for decades. Having built their own brand after producing gear for Assos in the 1990s, they still do contract production (like for the Laché London kit we featured a couple winters ago) in addition to their own gear. Kalas are best known for custom kit, producing for everyone from amateurs to top pros like those racing for British Cycling & the Czech National Teams. But they also produce some unique riding gear in their own branding as well.

One of those unique offerings is a foul weather kit based on the RainMem fabric. Like a number of other companies, Kalas has taken a technical fabric approach to keeping riders comfortable no matter the weather. Their slightly thicker, stretchy membrane based RainMem strikes a good balance between insulation and breathability to keep us riding all year long. We’ve been riding the standard, all black RainMem kit – bib shorts, jersey & warmers – through a full range of seasons to see how it functions & how it holds up. But Kalas will also print on it however you want as part of their full custom program.

Fabric tech

Kalas works with fabrics produced all over Europe, but the single 270g/m2 RainMem X3 fabric of this kit is Italian. The fabric itself is mostly polyester (85%) with elastane/lycra (9.5%) blended in. But it is the 5.5% polyurethane membrane that does a bulk of the work. While many companies that produce wet weather kit use a range of different fabrics for different parts of the kit (ie. jerseys vs. shorts vs. warmers), Kalas sticks with the same weight RainMem X3 throughout. That generally means the kit isn’t the most breathable, but rather offers excellent protection from all sides.

Kalas quotes the RainMem fabric as waterproof to a 10,000mm water column. That means it is going to do a pretty good job of keeping water out under most conditions. But in really heavy & extended rain it did eventually let some water in, although that also comes down to a lack of taped seams. Its breathability is rated at 11,000g/m2/24h. That puts it in the upper levels of breathable protection kit, but certainly nopt the absolute most breathable.


We rode in a complete set of the adaptable cold and wet weather riding kit. That includes a RainMem short sleeve jersey, regular bib shorts, arm warmers, and both knee & leg warmers. The modular layout meant that we could easily mix & match to suit a range of temperatures wider than the 0-10°C that Kalas officially lists for the fabric. Our RainMem kit is part of Kalas’ stock Passion collection, which basically means it sticks with all black, but with a heavy dose of reflective accents at the wide raw cut arm & leg grippers and across the back of all pieces. New stock fluorescent yellow versions are now also available.

There is not much overly unique in the pieces’ cut or features here. The 130€ jersey gets a standard, non-waterproof full-length zipper, an extended cut in the back with an elasticized drop tail, and typical three pocket layout.

The 130€ bibs use a six panel short design and a thick but comfortable ‘Endurance Carbonium’ chamois.

The 44€ arm, 44€ knee & 63€ leg warmers all get anatomic cuts and basic silicone grippers. The full length leg warmers use a reflective zipper at the heel.

Sizing from Kalas goes for a numbered scheme, similar to Italian cycling sizing. That means you should get out a tape measure and see where you fall in their charts. We pretty much went for size 4 (Large-ish) across the board for our 178-185cm tall, 75-80kg testers and had reliably comfortable, but not really tight fits. The fabric is very stretchy, so we would have sized down on the jersey for a closer fit if we did it again. But this was totally a cold weather kit for us, so the ability to add an extra baselayer under the jersey was helpful in extending its range.

Fit impressions

Kalas makes all of their kit in the Czech Republic, in Tábor, just down the street from the cyclocross course that has hosted a couple of World Championships and a number of World Cups in recent years. Pretty much every time we’ve turned pedals on the course in training over the last two seasons we’ve at least been wearing a set of RainMem knee or leg warmers.

Our test jersey (as mentioned above) is not quite race cut on all but our largest tester. With a more loose fit, we use it more as a thin jacket than a jersey. It is quite long on the back, doing well to cover your back parts while riding in the rain or snow. Sleeves are almost elbow joint long with the long reflective gripper, which keeps them stretched over warmers and seals up to keep water and wind outside. Wearing it without armies, some might not like the little gripper dots. But most of our time was spent combined with warmers, and the gripper didn’t bother any of us on the cool rides when were broke our guns out.

The shorts are the same fabric, from the legs up to the bib straps. They look a bit on the thick & heavy side, but feel comfortable against the skin with a nice amount of light compressive stretch. And when riding in temps below 10°C/50°F we never felt clammy even across the back. On the other side, their high cut offered nice insulation above the waist, with no air sneaking in when paired with the jersey. And the relatively long leg cut & extended grippers did well to seal out the elements, as the jersey did. The chamois is definitely bigger than we are used in most summer weight bibs, but gave good support for long days riding in the wet & cold building base miles.

All of the warmers again use the same fabric, and shaping the kept them in place well. Standing the anatomic cuts would bunch a bit, but will riding their fit was comfortable and never chafed, with the narrow silicone tape grippers holding them in place under the wide jersey & shorts grippers.

Ride impressions

We were curious & maybe skeptical at first of the thicker membrane based fabric. It looks & feels a bit more like neoprene than some of the other similar (and often more expensive) types of foul weather kit we’ve tested. But unlike neoprene, the RainMem did an admiral job of breathing well to let us push hard through our winter training without ever feeling overly sweaty inside, all the while keeping all wind out too.

In the end we rode the RainMem kit hard through two full winters now – through early autumn rides with occasional showers, then the deep winter freeze and snow rides, ultimately until spring rides ending in heavy rain or snow showers. And pretty much without fail, the fabric took it all, keeping us comfortable for the ride.

The RainMem kit served us best within temperature ranges just below freezing up to around 10°C. Riding below -5°C the jersey needed some insulation help from heavy baselayers. The bibs & leg warmers still did pretty well at those colder temps, and on the bike our legs & groin stayed mostly comfortable. But after long rides our cold skin told a bit of a different story, although that’s pretty common with most standard kit at sub-freezing temps.

Riding it above 10°C in the spring we did find the upper limits of the extra insulation & fabric breathability, most notably on extended climbs. At the same time, it was really welcome on spring rides that unexpectedly included heavy precipitation, keeping us warm & dry inside.

Durability wise, the RainMem kit has performed solidly as well. We ride with the kit on & off road, plus racing cross,  often pairing with a water proof trail short for wet winter mountain biking. Since the technical waterproofing is a function of the physical membrane (not fabric-treatment), the kit has survived many regular machine washings, with no drop in performance.

The stretchy fabric has taken the occasional trail scrape without much visible damage to the fabric surface. With that said a couple gravel & muddy road washout crashes have left some holes in our knees. The stretchy nature of the fabric has since made it relatively easy to stitch the cuts back up, to get back almost full weather protection on our knees.

Not such a big surprise to us, since we’ve seen similar performance with other waterproof fabrics, the leg warmers became our favorite pieces out of the kit. Extending high up into the groin, the lightly insulated & waterproof fabric makes them warmer than almost any other leg warmers we’ve ridden and almost completely impervious to road spray. Our  testers would routinely ride headlong into ice covered puddles & creek crossing with no fear of cold legs all winter.

So happy with their performance, our second tester went out and bought his own pair after I refused to let go of the original leg warmers myself. Now when I’m not out riding in them myself, they live in my Bikerumor cyclocross kit Rain Bag, ready to add warm & waterproof protection to any other kit I’m wearing when the weather turns without warning. I mean, whenever I need leg warmers (or even knee warmers for that matter) why not add waterproofing to the mix as well. And I’d certainly feel better crashing in these, than some more expensive to replace options


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