Over 700kms through the rugged Kimberley makes the annual Gibb Challenge one of Australia's toughest mountain bike journeys.

The Gibb River Challenge riders are prepared for all sorts of terrain along the 700km journey. (ABC Local:Clancy McDowell)

It's rare to find the words "gruelling" and "enjoyment" in the same sentence. But the annual Gibb Challenge conjures many more adjectives and superlatives.

It's a 700 kilometre bike ride from Derby to El Questro, along what's described with tongue in cheek as the Kimberley's very own "super highway" - the Gibb River Road.

The road can be tough going in a comfortable four wheel drive, but every year, riders are drawn from all over the Kimberley and around the world to pedal and sweat their way through the dust. Their reward is the breath-takingly beautiful country along the way.

Sally Roberts and Kate Hooper talk of the downhill into Home Valley as "unlike anything you've ever seen".

"There's an amazing hill you go down and it's just spectacular. You look across that vista and it's like a painting. You have to pinch yourself."

Leith McDonald made the journey from southern Queensland to ride the Gibb this year. She knew what to expect as she's done it before in a four wheel drive and says it's wonderful to see the red dirt country again.

All the Gibb Challenge teams raise funds for good causes each year, this time the Kyle Andrews Foundation is the main beneficiary.

In 1998 Kyle had to go to Perth for leukaemia treatment and hoped some of his young friends on the cancer ward could visit Broome and Cable Beach because they'd feel better. Kyle didn't survive, but the foundation that takes his name brings sick kids to Broome.

"This was Kyle's dream," says the Foundation's Lee Anderson. Lee says the support of the Gibb Challenge this year has been a major boost, with the Foundation now almost two years closer to achieving goals they've dreamed of for a long time.