Whether water’s falling from the sky or splashing up from the trail, waterproof mountain biking trousers can make a huge difference to how much you enjoy wet weather riding.
Keeping dry means that you can spend longer on the trails, makes the post-ride clean-up operation much easier, and also helps you avoid the dreaded soggy chamois!
Waterproof mountain biking trousers are generally not cheap, so you’ll need to seek out waterproof and breathable materials that stand up to abuse on the trails to make sure that your investment is worthwhile. However, there are bargains to be had, too.
These are the best waterproof mountain bike trousers tested in our recent winter group test.
Not sure what you’re looking for? Our full buyer’s guide is at the bottom of this article.
The best waterproof MTB trousers, as rated by our expert testers
The following products scored at least 4 out of 5 in our test.
- Decathlon Rockrider All-Mountain: £40
- Fox Ranger 3L Water: £140 / $175 / €150
Decathlon Rockrider All-Mountain
- Material: 88% polyester, 12% elastane with DWR treatment
- Sizes: S, M, L, XL, XXL, XXXL
- Weight: 307g (M)
- Price: £40
For the money, these are amazing. Even though Decathlon claims the trousers to be just water-resistant, not fully waterproof, the triple-layer seat and calf panels only started to soak through after long wet-weather rides.
The thighs and waist are made from a stretchy, breathable fabric, with a DWR coating and ample room for knee pads. This treatment does a good job of making water bead and run off, and even once the material wetted through, the trousers remained comfy and didn’t stick to our legs. The waist is secure enough to stop them slipping down, too.
A raised rear prevents crud splashing onto your back, while elastic ankle cuffs keep water from splashing up inside. The stretchy, lightweight material feels snug and dries fairly quickly.
Watch out – sizing is on the small side, especially around the waist and crotch, so consider going up. The two zipped pockets also aren’t big enough to comfortably store a smartphone.
Fox Ranger 3L Water Pants
- Material: Three layer, 94% polyester, 6% elastane with DWR treatment
- Sizes: 28, 30, 32, 32, 36, 38, 40in
- Weight: 330g (30in)
- Price: £140 / $175 / €150
In the correct size (we’ll come on to that), the fit on these Fox Ranger 3L Water Pants is perfect and sculpts to the riding position well.
There’s ample space for knee pads, and tapering at the calves means they don’t flap in the wind. Elastic ankle cuffs stop water splashing upwards and the legs from riding up.
A ratchet strap provides reliable and secure waist adjustment and stops the trousers falling down once wet. They didn’t soak through during testing, keeping us totally dry after hours of torturous wet weather riding, even once they were covered in mud.
The material feels soft and doesn’t stick to the skin, even when sweaty. There are two zipped pockets, which are large enough for essentials; a smartphone is a squeeze and causes a bit of bunching, but doesn’t make the pants uncomfortable to wear.
As for sizing, try before you buy, because the waist sizes up quite large and adjustment is limited. In contrast, the legs are quite short, so we ended up pairing these trousers with waterproof socks. They get quite hot on climbs, too.
The following trousers scored less than 4 out of 5 in our reviews but are still worth considering.
Gore C5 Gore-Tex Paclite
- Material: Gore-Tex Paclite Plus 100% polyamide
- Sizes: S, M, L, XL, XXL
- Weight: 167g (M)
- Price: £180 / $200 / AU$265 / €200
True to Gore’s claims, the C5 Paclite trousers kept us dry during testing and didn’t wet through or leak during the post-ride hose-down.
There’s a raised panel at the rear, which helps reduce the amount of water and mud splashing onto the small of your back. At the waist, a drawcord, fastened with a knot, stops them falling down once wet.
They fit true to size and, while there isn’t much stretch in the fabric, there was no excess tension around the crotch or hips. The large, calf-height zip makes it easy to take them off with shoes on. They’re light too, at 167g for our medium pair.
However, the lack of thigh vents means these trousers get quite hot and, once we got sweaty, our legs stuck to the inside. We found they tugged knee pads down, especially when pedalling seated.
The ankle cuff poppers aren’t as good as an elasticated cuff and don’t feel very refined, considering the high price, and we struggled to fit a modern smartphone in the single pocket.
Alpkit Parallax Men’s
- Material: 2.5-layer, 100% nylon with PU membrane
- Sizes: S, M, L, XL
- Weight: 182g (S)
- Price: £80 / $100 / AU$147 / €90
The Alpkit Parallax trousers deal with sweat well, the inside only getting wet on very slow climbs. Once damp (we’ll come on to waterproof performance) they were still comfortable against our skin and didn’t cause knee pads to fall down.
We like the light feel and the way they easily pack into the supplied bag. The elasticated waist and adjustable pull-cord meant we could tighten the pants so they didn’t fall down, even when covered in mud and water.
On the flip side, the fit is fairly baggy, especially around the calves, where the material flaps in the wind. Adjusting the Velcro ankle cuffs doesn’t reduce the volume either.
While the trousers resisted full water penetration during testing, the 2.5-layer material did wet-out quickly, with the outer layer getting soaked through and making the trousers feel damp on the inside, even though the water didn’t get all the way in.
This suggests the DWR coating can’t cope with the abrasion and rubbing of bike use. When we hosed them down at the end of a ride, the seams leaked, letting water in.
These are also available in a women’s cut.
Buyer’s guide: what to look for when buying waterproof MTB trousers
Waterproof materials are typically made up of two or three layers including a waterproof membrane, often backed by a softer material against your skin and sandwiched between a tougher external layer (or ‘face fabric’).
A fabric’s waterproof rating will demonstrate whether it’s able to stand up to drizzle or heavy downpours, and is measured by a material’s resistance to water before it leaks through, conducted under lab conditions.
The higher the number, the more resistant to water ingress and bad weather conditions the material will be, with ratings of 16,000mm and over suitable for wet conditions and 20,000mm and above among the best.
Seams are an obvious weak point in any waterproof fabric, so they are often sealed and taped internally to try and stop water getting in.
DWR treatment (Durable Water Repellent) is often used on the external surface of the fabric to help precipitation or trail spray bead off the surface.
As this treatment degrades over time with laundry cycles, it can be reapplied to the fabric using reproofing sprays or washes. Look out for PFC-free DWR treatments for the most environmentally friendly solution.
Mountain biking trousers aren’t often made completely from waterproof materials, but instead use a combination of strategically placed panels of waterproof, water-resistant and breathable fabrics to give the best overall performance.
The areas that typically get wettest include the seat and backs of the legs, from spray off the back wheel, so these usually feature the most robust waterproof materials and taped seams.
Some trousers will feature areas of DWR-treated water-resistant fabrics, such as on the front of the thighs, because these are less likely to get as wet. The idea here is to provide some protection from rain or trail spray, though the fabric isn’t necessarily fully waterproof.
Breathability and ventilation
The flip side of waterproofing is breathability, as anyone who’s sweated buckets inside cheap waterproofs (whether that’s a jacket or trousers) will be all too aware.
Maintaining airflow, ventilation and sweat evaporation while keeping water out is the holy grail for any waterproof product and can be achieved by using high-tech breathable fabrics and strategically placed vents.
Some trousers have zip-able vents to help maintain airflow when it’s not bucketing it down or when riding uphill, typically found on the upper thighs.
The Water Vapour Transmission rating (WVTR) measures how breathable materials are, by testing how much water vapour can travel through the material in given conditions. The higher the rating, the more effective it will be at keeping you comfortable during higher intensity riding.
Look for ratings of 20,000g/m²/24hr and above for good breathability.
Fit and cut
Waterproof riding trousers should fit similarly to conventional MTB trousers, with a tapered lower leg to reduce the risk of getting the fabric caught in the drivetrain or flapping, and an adjustable waistband to tailor the fit. A higher cut at the back also gives extra splash protection.
Ideally, you’ll want a snug but non-restrictive fit: too loose and you could risk the trousers sagging; too tight and they’ll be uncomfortable or restrictive. Look out for elastane blend materials to help give extra stretch, and make sure that there’s plenty of room for you to wear knee pads underneath too.
Some waterproof trousers are designed to be worn over your normal riding trousers, with full length zips for ease of getting on and off, and a slightly looser fit so you can layer up underneath.
Pockets with a waterproof lining and waterproof zip are best for storing valuables.
These should be located away from the hip area, such as on the outer thigh, so they don’t interfere with leg movement when pedalling.
Besides countering the elements, waterproof trousers must also be robust enough to endure the rigours of mountain biking, so look out for additional features including abrasion-resistant panels.
If you’re planning on mountain biking at night, reflective details are another bonus.