Every April, the town of Gloucester, three and a half hours north of Sydney, hosts one of the most challenging and enjoyable gravel riding events in Australia or New Zealand. Based in the World Heritage-listed Barrington Tops National Park, Thunderbolts Adventure is brought to you by Graveleur.

All photos accompanying this article were taken at prior Thunderbolts Adventure events by Ready Aim Media.

How Thunderbolts Became an Icon

As of 2026, Thunderbolts Adventure has been running for ten years and is sold out for 2026.

It offers three course options. The hardest is the Monument, a 173-kilometre epic with over 3,500 vertical metres of ascents. Riders will get up a little earlier this year to attend the ANZAC Day Dawn Service with the people of Gloucester. Then it’s down to the start to spend the rest of the day pushing mind and body over some of the best gravel roads in Australia. To finish, you must average 18 kilometres per hour within the 10 hours that the route is supported.

To better understand what it means to climb 3,526 metres in a single day, consider that Mount Kosciuszko is the highest mountain on the Australian mainland but is “only” 2,228 metres above sea level.

If that sounds just a bit out of your league, then you may want to try the Colt. This is a relatively new addition to the Thunderbolts Adventure and involves riding 93 kilometres and ascending 1,460 vertical metres.

There is also the Remington, designed for families and those who just want to take in the scenery, involving 46 kilometres and 602 vertical metres.

Starting as a one-day epic in 2017, Thunderbolts Adventure evolved into a 2-day, overnight backpacking event in which you camped out at Moonan Flat and ate a dinner supplied by the local pub. The next morning, you rode back to Gloucester.

The challenge of catering to more than two hundred hungry riders has made that an impractical option. For those who want a multi-day adventure, however, the organisers this year have included an option called The Pilgrim.

The Pilgrim gives bike packers a midpoint destination for their multi-day rides. They can ride two days or five days, 250 kilometres or more than 500 kilometres. They just need to arrive in Gloucester on Saturday night, in time for dinner with all the other riders at the Avon Valley Inn.

Without a doubt, one of the reasons riders love the Thunderbolts Adventure so much is the challenge it gives them. In its first year, 2017, the course was even more savage: 230 kilometres with 5,000 metres of climbing. Gradients regularly exceeded 10%.

The 2026 version may seem like a tamed descendant of that wild beast of a course, but it’s no house pet. There's a 7-kilometre ramp with an average grade of over 10%. Riders don't know whether to laugh or curse as they battle their way up it.

One of the benefits is the gorgeous countryside. You'll travel through multiple climate zones in a single day. There may be sunshine in Gloucester, but you could face deep winter conditions on the plateau.

The 2024 Thunderbolts Adventure delivered near-freezing temperatures, high winds and heavy rain at the top. Riders shared heat packs, wrapped their feet in foil, and felt a sense of togetherness that has become all too rare in our lives.

As organiser Mike Israel explained, "It's an adventure, and for an adventure to be authentic, you need to be prepared to maybe go a little bit hungry and more than a bit cold. In the moment, you might feel like it’s too hard or even like you’re going to fail.

“But later at the pub, you’ll be telling your friends what an epic day it was.”

Those who have ridden in Thunderbolts Adventure agree.

“The scenery was next level, just awesome. Fun factor rates very high,” one rider, Laura Renshaw, told a mountain biking magazine. But she added, “I have to stress that training is a must. Make sure you’re getting some big rides in, back-to-back days, leading up to the event.”

Another rider, Andy, said, “It was such a terrific event, with a delightful balance of badassery, conviviality, community and unpretentiousness. Big words for big memories.”

Who Was Captain Thunderbolt?

Thunderbolt's Adventure is named for a famous bushranger who roamed the area around Barrington Tops and was married to a local Worimi woman. He was born with the much less interesting name of Frederick Wordsworth Ward and had an uneventful life until he ended up in prison after helping his cousin sell a mob of stolen horses.

His wife, Mary Ann Bugg (Australia’s first female bushranger), helped him escape from the notorious British prison on Cockatoo Island. He swam to the mainland and disappeared into the bush.

Frederick got his new name, Captain Thunderbolt, during a robbery when he pounded so loudly on the door that the frightened people inside said it sounded like a thunderbolt had struck the place.

Captain Thunderbolt was killed near the town of Uralla, about two hours by car up the Thunderbolts Way from Gloucester.

Just in Case You Need More

If you finish Thunderbolts Adventure and think to yourself, "I'd like more of that," then you should know that it's part of the Bushranger Series, a three-event gravel series for the hardiest of athletes. Each event is named after a real bushranger associated with that region.

If you complete the series in a single year, you win a limited-edition Bushranger Series belt buckle.

The other two rides in the series are Clarkes Gambit, in August at Nelligen on the NSW South Coast, and Marys Mayhem in Mudgee every October.

Advice for First-Timers

If you are tackling Thunderbolts Adventure for the first time, be honest with yourself. Whether you pick the Monument, the Colt, the Remington or the Pilgrim, you'll have a fantastic adventure with other great people. You won’t impress anyone by picking a route that's out of your reach.

Start your training at least eight weeks out. Make sure you're up to the challenge that you've selected.

Be prepared for the course to be unmarked. You can download the GPX file before you leave home. And don't expect to rely on mobile coverage, as there is essentially none.

The event can be as social as you make it. Most people group up with others who are travelling at a similar pace. You will almost certainly go home having made new riding friends.

Will Thunderbolts Adventure Last Another Ten Years?

Over the years, this event has survived many a crisis, including COVID, landslides, and extreme weather. Yet, it keeps on drawing riders from all walks of life who seek adventure and that community vibe that is often lacking in our everyday lives.

With its focus on finding adventure and mateship while riding a bicycle in a remote wilderness region, it is hard to imagine riders not continuing to show up.

Learn more about Thunderbolts Adventure and its sister events, Marys Mayhem and Clarks Gambit, on Graveleur’s website.