Our Story
Born from triathlon. Built for adventure.
Onni started with a problem every triathlete knows but nobody talks about — the brutal moment you go from soaking wet to a bicycle seat.
A dream, an injury, and a problem worth solving
In 2015, Basson Engelbrecht was doing what he'd spent most of his life doing — training. As a professional triathlete with his sights locked on the 2016 Olympics, he was racing across the globe, pushing his body to its limits in pursuit of one goal.
But in the final stretch of that journey, a serious injury changed everything. The Olympic dream was over. The running shoes came off for the last time.
What stayed with him, though, was something far less glamorous — a problem he'd lived with through every race, every training session, every early morning: the transition from water to bike was genuinely awful. Soaking wet, climbing onto a bike seat, then grinding through kilometres of friction, chafing, and discomfort. The shaving. The rawness. Every triathlete knows it. Nobody had solved it.
So Basson decided to solve it himself.
From factory floors to finish lines
What started as personal frustration became a full-blown mission. Basson visited leading underwear manufacturers around the world — from fabric mills to production lines — studying materials, construction techniques, and performance engineering. He wasn't looking for "better underwear." He was looking for underwear that could survive the most punishing test in sport: soaking wet to bicycle seat, without a hint of chafe.
The result was Onni — performance underwear engineered from ice-silk fabric that dries fast, sits flat, moves with you, and eliminates friction where it matters most.
He gave pairs to his training mates first. Then their mates wanted them. Then word spread through the triathlon community, then road runners, trail runners, rugby players — anyone who moved hard and demanded more from what they wore underneath.
In South Africa, Onni quickly became the go-to for athletes who refused to settle for ordinary underwear. What began as one triathlete solving his own problem had become a brand serving an entire sports community.
A mate, a move, and the Manly surf
Charl and Basson weren't just friends — they were training partners. The kind of mates forged through 5 AM swim sessions and long runs where you talk about everything and nothing. They'd raced together, suffered together, and were among the first to wear Onni when it was still just a prototype and a dream.
In 2022, Charl relocated to Sydney. And almost immediately, he noticed something: Australia had a massive, active outdoor community — trail runners, surfers, cyclists, weekend warriors — but nobody was serving them with the kind of performance underwear that had taken off in South Africa. The gap was wide open.
The idea simmered. Then Basson came to visit.
What was meant to be a holiday turned into something bigger. Basson fell completely in love with the Australian outdoor lifestyle — the trails, the coastline, the culture of getting outside and moving. Getting him out of the Manly surf was a battle most days.
Somewhere between the waves and the long walks, the conversation turned serious. If Onni could serve athletes in South Africa, why not here? The Australian market was bigger, the outdoor culture was deeper, and there was nothing quite like Onni on the shelves.
In early 2025, Onni Outdoor launched in Australia.
What we believe
We're not a big corporation with a marketing department telling us what men want. We're two mates who've spent thousands of hours training, racing, and living in the gear we sell.
We believe your underwear should be the last thing you think about — whether you're grinding through a trail run, sitting through a long meeting, or paddling out past the break at sunrise. It should just work.
We also believe that doing right by the planet isn't optional. Every Onni order ships in compostable packaging, delivered by carbon-neutral shipping, wrapped in FSC-certified materials. Because the outdoors gave us everything — this brand, this lifestyle, this story — and we intend to protect it.
From South Africa to Sydney — and wherever you're headed next
Onni started in the transition zone of a triathlon. Today, it's worn by runners, cyclists, surfers, gym-goers, tradies, office workers, and blokes who simply want underwear that doesn't let them down.
We're still a small team. We still test every product ourselves. And we still believe that the best underwear is the kind you forget you're wearing.
Welcome to Onni.