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78 reviews
Jet Black

Full-length luxury overpants for committed commuters come rain, hail or deluge. 3 layer HydroFoil™ Plus fabric keeps your long pants dry while spiral zipped leg gussets let you pull them on and off over your shoes without any excess fabric to snag your chain.
  • Lightweight waterproof-breathable 3 layer HydroFoil™ Plus fabric with fully tape-sealed seams for maximum waterproofness.
  • Zipped fly with gripper elastic waist keeps them hitched up.
  • One piece gusseted crutch.
  • Articulated knees.
  • Zipped rear pocket.
  • Turns into itself to form a tidy package in your backpack or pannier.
  • Hazard!™ reflective labels and piping on lower legs.
  • Zip leg gussets expand to pull over your shoes, then zip up to avoid chain suck when pedalling.
  • Waterproofness: 23,000 mm hydrostatic head with a water-repellent finish.
  • Breathability: 33,000 gm per sqm per 24hrs.
  • Designed & made by us in Aotearoa | New Zealand.
+Inseam Length

The garment's inside leg measurement from crotch to cuff.

83 cm 85 cm 87 cm 89 cm

  Weight: 250 gm

Specifically developed for high aerobic activities, HydroFoil™ Plus combines a lightweight ripstop nylon shell with a composite membrane that is completely waterproof, totally windproof and extremely breathable. The outer fabric is the latest new-generation Pertex® Shield+ membrane. It is more than twice as breathable as most other quality waterproof-breathable fabrics, and has a small amount of stretch allowing a closer fit. The outer fabric is treated with a water repellent finish that encourages rain to bead up and roll off, while there is a lightweight tricot mesh on the inside for greater durability and improved moisture dispersion.
  • Composition: 100% nylon with PU laminate.
  • Waterproofness: 23,000 mm hydrostatic head with water repellent finish on face fabric.
  • Breathability: 33,000 gm per sqm per 24hrs.

Night travel is a spooky experience. Many Ground Effect garments feature our Hazard!™ reflective logo and piping to help remind traffic that we're on the road too.

+More than Kiwi Made
Ground Effect clothing is crafted right here in Aotearoa | New Zealand. Has been ever since we started back in 1994. Manufacturing locally works for us. We operate a quick-response system - holding minimal stock of any one item, but churning out a few more quick-smart when the pile gets low. The upshot is that we are seldom caught with our shelves empty, so orders get despatched the same day you place them.



+Benefits of 3/4 vs full-length over trou?
We've extensively tested both full-length and 3/4 waterproof pants over the years. In our experience 3/4's provide the best trade-off between functionality and performance in most conditions - especially for mountain biking, bikepacking and touring.
  • They are easy to whip on and off over your shoes.
  • Repel rain from the most exposed areas - your bum and thighs.
  • Avoid 'chain suck' at your ankles.
  • Minimise overheating when pedalling hard.

However full-length over trou are sometimes best - notably for commuting when you want to keep your long pants dry, or when touring to really cold and/or wet places.


  • All Ground Effect clothing enjoys a warm 40ºC machine wash. Try to avoid cold-water detergents and those with bleach, 'oxygen whitener' or fabric softener.
    • The cold-water varieties have little enzymes that are super-charged to brave the cold but can damage technical fabrics and cause skin irritation.
    • Bleach rots natural fibres like merino, strips the dye, attacks laminates of waterproof fabrics and can also cause skin irritation.
    • Sodium Percarbonate (the main ingredient in oxygen whitener) can make colours run.
    • Fabric softener and stuff containing it like wool wash destroys the water repellent finish on waterproof and water resistant fabrics, and can cause colours to run.
  • As a rule of thumb, a product that is easy on the planet is also easy on your body. Select a mild plant-based soap like Ecostore, Earthwise or Aware.
  • Hand washing is sometimes the only option on tour, but a washing machine rinses more thoroughly and is preferable if you have the choice.
  • Most Ground Effect gear dries super-fast so hanging on the line or drooping over the bedpost is generally the best option. High heat can damage some fabrics so if you do take your threads for a spin, set the device on 'medium' or 'warm' rather than hot. A lap in the dryer is recommended for your rain jacket, after it has dried on the line, as it helps recharge its water repellant finish.

  • Wash with any of the plant-based products listed above. You can also use a specific sport wash like Grangers Extreme Cleaner, Nikwax Tech Wash or Atsko 'Sport Wash'. Around NZ$30 from most outdoor shops. Any stubborn stains should be dabbed not rubbed clean. For grease spots you can use a degreaser like Swarfega. It's aggressive stuff though so take care - it might be best left alone as added character.
  • Keep it clean, but don’t wash too often. General wear along with washing progressively removes the water repellent treatment from the outside the fabric. This treatment helps rain to bead and run off - and enhances the overall performance of the fabric. Dirt, body oil, sunscreen and sweat also attack the water repellent treatment and can cause the waterproof-breathable membrane to delaminate. Wash frequency depends on how often and how hard you use your garment. We suggest at least a couple of times a year - certainly after a muddy mission, an especially sweaty ride, or say half a dozen sessions in the rain. Use your judgement - if the garment looks dirty, the fabric is 'wetting out’ too quickly, or feels clammy then it's probably time for a clean.
  • When the fabric starts 'wetting out', it's time to apply some love. You can help restore the water repellent treatment after washing by line-drying your jacket, then chucking it in the dryer using a warm (not hot) cycle. This 'recharges' the treatment so it lasts a bit longer. When this trick no longer does its magic you can beef up the original treatment to some extent with a product like Nikwax TX Direct - $39 from Ground Effect. A bottle is good for two or three rounds with your jacket. The effectiveness of this process depends on the age and condition of your jacket.
  • Note that while the fabric's wetting-out impairs performance, particularly breathability, the HydroFoil laminate should still be waterproof.
  • Always ensure your HydroFoil garment is completely dry before storing. Putting it away damp can destroy both the water repellent finish and the waterproof coating. Hanging on a hook or coat hanger is best. Take care of your gear and it will take care of you.

  • Items are generally packed and sent the same day your order is received.
  • Costs $9 by overnight courier within New Zealand.
  • NZ$12 by tracked airmail to Australia.
  • Around NZ$15-25 by tracked airmail to destinations elsewhere in the world - calculated in our shipping cart as you check out. 
    • More shipping and tax details in our FAQ.
    Customer Reviews
    5.0 Based on 78 Reviews
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    Filter Reviews:
      Geoff H.
      New Zealand New Zealand

      They do the job, no question.

      The problem I had with the 3/4 length version was rain water running down my legs and into my boots - wet socks and boots. With this length, the boots are covered and my feet stay dry. Happy days. They also go some way to keeping my legs warm. As it is winter I have yet to suffer perspiring in them, not sure if they will breathe. Getting them on and off is trouble free with the zippered cuffs, though I take my boots off before removing the trou to keep dirt out of the legs. Have yet to ride in a real downpour which usually results in water getting me wet around my waist. Not sure if that is the over trou not being pulled up high enough or the jacket either riding up or bunching and puddling water. I can say that while the material is reasonably new, it DOES NOT LEAK! I hope these last as long as my other GE gear, but I get the impression that even with care the material and its water proof properties will slowly deteriorate. Fingers crossed for five years plus of service.

      Connor M.
      Australia Australia

      I'll take your entire stock!!

      Absolute beauties! Waterproof & breathable to the point you can wear these babies under water & walk out bone dry (obviously not true but you get the gist). My wardrobe is slowly becoming a Ground Effect showroom and I make no apologies!

      Shane C.
      Australia Australia

      Great pants!

      Bought the Splashdowns for my daily commute to work in the Sydney rain. I’m very pleased with them, great quality, light, pack away easily and keep me totally dry. I’m a size 34” waist and ordered a large size and they fit perfectly, a good amount of stretch in the waist band for a pair of pants underneath. Thanks GroundEffect for making a fantastic product!

      Paul B.
      Australia Australia

      What took me so long . . ?

      Bought these mid June 2023 however had to wait for a heavy summer rain to fully explore the effectiveness of these waterproof pants. First time in a long time I arrived home with dry shorts after a hour plus commute in the rain. I am very impressed. Why I didn't buy these Ground Effect pants years ago is a mystery. They work and a lot better than I expected. I was wearing knee warmers due to a knee injury and experienced no sweating on the inside. Being 178 cm tall, 76kg I find the large size fits over my baggies with no problem. Large openings on the legs means getting them on in a hurry while wearing shoes is not an issue. For me the fit is good and comfortable on my MTB and buying the large size I assume I also get a longer leg, than the medium, so that my shoes also benefit from some rain protection. Thanks to all at Ground Effect New Zealand and next time I'm home, I'll drop in for a chat.

      Stu K.
      New Zealand New Zealand

      New splashdowns

      Just completed the 2023 Geyserland Mega, 5 days of riding from Rotorua across and up into the Timber Trail, Piopio, out to Marakopa on the West Coast then back to Rotorua. We lucked out with the weather big time, and ended up riding in the rain for 3 days. It was crazy wet. Luckily I had bought some Splashdowns for the trip, and spent alot of time riding in them. They are a good mix of loose fitting enough to not be restrictive, but equally not so loose that they get caught up in stuff. The first afternoon in the rain I struggled to keep warm, but then decided to put the splashdowns on and it made so much difference, keeping me warm and making riding in the rain almost enjoyable (probably because after so much rain it became normal !! I feel the cold, so got these full length ones instead of the Helter Skelters, and glad I did. They work really well. Another great product from Ground Effect.