ON the dusty roads of Afghanistan, a quietly determined revolution is taking place.

Along the highways near the outskirts of the capital Kabul, the women's national cycling team can be found pushing against age-old gender stereotypes and shattering deep-rooted taboos.

While men and boys on bikes are a ubiquitous sight across the country, for women to do likewise remains hugely controversial. Straddling a bike seat is viewed as a provocative and immoral act for a woman - and one that risks dangerous repercussions.

Mentoring this group of women is Shannon Galpin, who is attempting to challenge one of Afghanistan's biggest enduring social stigmas. In 2009, she herself broke new ground by becoming the first woman to mountain bike across the country's rugged and mountainous terrain.

Galpin's own story began nine years ago in a project to tackle gender violence. The 40-year-old from Colorado - who will give a talk at the Edinburgh Festival of Cycling this month - coined the idea for Mountain2Mountain, a non-profit organisation to educate and empower women.

The catalyst was Galpin's own harrowing experience when she was beaten, raped and left for dead. Horrifically her younger sister was sexually assaulted just over a decade later. "I was raped when I was 18 and nearly killed," she says. "Then, 12 years later, my sister was raped on a college campus."

At the time her sister was attacked, Galpin was pregnant with her daughter, Devon, now 10. It was her overwhelming instinct that she didn't want her child to grow up in a world where the threat of violence against women lurked like an omnipresent spectre.

"I realised the world needed to change for women and I needed to be part of that," she says. "It was an almost overnight decision to start Mountain2Mountain."

Galpin, a fitness trainer and pilates instructor, packed in her job, sold her home and headed to war-torn Afghanistan - chosen for its reputation as one of the worst countries in the world to be a woman.

Over 19 visits to date, she has been involved in everything from setting up reading classes in women's prisons and curating powerful photography exhibitions to launching rural midwifery training programmes and building a school for the deaf.

Six years ago Galpin cycled 140 miles across the Panjshir Valley, using her bike as a conversation starter with the elders in remote mountain villages and the Afghan people she would encounter along the way.

"I didn't go to Afghanistan ever intending to ride a bike," she says. "When I started my work in 2008 it was much more traditional gender projects. It was a year-and-a-half after working there, on my third visit, that I first rode my mountain bike.

"Afghanistan was one of the only countries in the world where women weren't allowed to ride bikes. While I saw boys and men all over the country riding bikes - there are perhaps as many bikes as there are cars - I never saw any girls or women."

After speaking with human rights activists, Galpin discovered that the bike remained taboo for women. "Afghan women are not allowed to ride bikes, but bikes are an amazing social justice vehicle," she says. "It increases access to school and reduces gender violence. It also increases access to medical care. We see that all over south-east Asia and throughout Africa. But if girls aren't allowed to ride bikes, we can't use what is a really simple tool."

Torn by decades of conflict, the past 35 years have seen Afghanistan occupied by both communist Soviet troops and US-led international forces, and ruled in between by militant groups and the oppressive grip of the Taliban.

The Taliban's version of Islamic Sharia law saw women and girls banned from going to school or studying, working, leaving the house without a male chaperone, showing their skin in public or being involved in politics.

Since the fall of the Taliban in 2001, women's rights in Afghanistan have slowly improved under the administration of former President Hamid Karzai, but it remains a patriarchal society.

"As a foreign woman, I was considered an honorary man and so had a lot more freedom than the Afghan women," says Galpin. "That allowed me to push on some gender barriers as a means to understand the issues from a different perspective."

Over a dozen visits to Afghanistan, Galpin mountain-biked across the country. "I would attract a crowd of men and boys who were curious as to who I was and why I was there," she says. "The bike became an icebreaker. It opened up conversations on the side of the road. I was able to ask questions about their homes, families and community. I would ask: 'Why can't girls ride bikes? Would you let your girl ride a bike?'" The answer was always a resounding: no.

It wasn't until four years after her first visit to Afghanistan that Galpin heard about the women's national cycling team. "It was a complete surprise," she admits. "I never thought I would see women riding bikes that soon and certainly not as an organised team."

She met with Abdul Sadiq Sadiqi - the country's first professional cyclist - who is coach and president of the Afghan Cycling Federation. He also founded the men's and women's national teams, teaching his own daughters how to ride bikes in the hope of encouraging other families to follow suit.

"When I met them it had been about two years since the women's team had been set up and they were just starting to race," says Galpin. "They were on rusted bikes with derailleurs and brakes that didn't work. They were using a men's extra-large bike for a small, petite young girl. But they were riding and having so much fun. The joy was radiating out of them."

Women on wheels

Galpin immediately pledged her support to the venture. Last year, she struck a sponsorship deal with women's cycle manufacturer, Liv, which supplied brand new bikes, helmets and equipment. Galpin stresses, however, that her role is purely as a mentor and it is the Afghan women themselves who are driving change.

There is a core of eight women in the team, though 20-30 others regularly turn up to train. It is their dream, says Galpin, to represent their country at the Olympic Games but she admits there is still much work to be done.

"When they have competed in bigger competitions such as the Asia Cycling Championships in Astana in Kazakhstan last year, neither of the girls who raced could finish," she says. "The distances were just too long and the racing too fast.

"That is the offset of having very few roads to train on. It is very unsafe: not only are they targeted [by opponents to women cycling] but there are IEDs (improvised explosive devices) and roadside bombs. There are few areas they can safely train on paved roads. Often their rides are cut short. They will ride for maybe 20 miles, then not get another ride for four days. They are competing against girls that train every day."

Encouragingly, Galpin recently discovered other pockets of the country where women are cycling. In the Bamiyan province, one young woman, Zahra, has started teaching girls to ride bikes, allowing them to travel back and forth to university.

"I have seen young girls riding in two other areas of Afghanistan within the last year," says Galpin. "They talk about it not as a means to race or compete, but as a means of equality. In Bamiyan, the boys can cycle [to university] in 15-20 minutes, but it takes the girls an hour or more to walk.

"Zahra said: 'That's not fair, we should be able to have the same access to education.' She started teaching other girls to ride so they had transportation - no men were involved. It wasn't a case of them needing a man to teach them or a coach to take them out so they could ride safely: what they are doing is even more radical."

The dangers for women who choose to ride bikes are considerable: rocks are thrown at them, insults hurled and their families criticised. Given all that, why cycle?

"Because they feel it is their right," says Galpin. "To them this is not a gender-specific activity. They believe they have the same rights as their brothers. The girls on the team talk about having the opportunity to raise the Afghan flag in other countries.

"When we talk about the risks, they keep coming back to that same issue: 'Change doesn't happen if we stay at home, change only happens if we ride and use our voices.'"

Galpin herself has received death threats. "That happened even when I was doing work that was more traditional in the women's prisons and education," she says. "I got it from the extremist side because it was women's human rights work and activism, but I also got it from Americans, who felt I was helping terrorists by working in Afghanistan."

In addition to her humanitarian work with Mountain2Mountain, Galpin founded the activist organisation, Combat Apathy, in 2013. "I wanted to be able to be very vocal about rape, gender violence, sex trafficking and the assault on women's rights around the world," she says.

"Combat Apathy is a space for me to use my own voice and speak openly as a rape survivor and sister of a rape survivor, to delve into some of the more controversial subjects."

She hopes a forthcoming documentary film, Afghan Cycles - due to be released next year - will help inspire and raise support for women who are riding bikes in other countries where it remains controversial.

Galpin is also working on a new initiative called Strength In Numbers, which uses two wheels as a symbol of women's freedom and a tool for social justice. It is due to launch in the US next year and will then be rolled out to other locations soon afterwards.

Following her appearance at the Edinburgh Festival of Cycling, Galpin will fly to Afghanistan for what will be her 20th visit. She will continue her work with the national cycling team and meet with a group of young women mountaineers who plan to climb Noshaq, Afghanistan's highest mountain.

Galpin, named National Geographic Adventurer of the Year 2013, draws comfort from her part in helping create a safer life, not only for her daughter, but for other young girls around the world.

"By the luck of the geographic passport, I was born an American woman in the 1970s and from a middle-class family," she says. "I have every opportunity and I have a voice. I need to make sure I am using my voice and opportunities to fight for women who don't because I would hope that other women would do the same for my daughter, Devon, if the tables were turned."

Already, the budding shoots of change are there. Galpin recalls a recent trip to Afghanistan, where she went out on a cycle with two young women including Zahra, who had started teaching her classmates how to ride their bikes to university.

"We were cycling in the shadows of the Buddhas that the Taliban had blown up and this posse of young boys decided to hook on and ride with us," says Galpin. "They were asking: 'Why are you riding? What is going on?'

"After an hour or so, one of the boys - he was teeny tiny, probably only about six or seven - came up and pulled on my shirt sleeves. He told me that, after watching these two girls riding, he was going to go home and teach his little sister how to ride a bike.

"That, for me, is what it is about. It isn't going to come from me as an outsider, but because someone sees an Afghan woman riding a bike and realises that is OK."

Shannon Galpin: Pedalling A Revolution is at the Edinburgh Festival of Cycling on June 17. For more information, visit edfoc.org.uk