And, after four years of hard graft, the then 28-year-old Welshman wasn’t about to abandon his Olympic dreams at the bottom of a steep Greek hill. Wheel or not.

Instead he lobbed his bicycle over his shoulder, ran up the hill to the next wheel station, swapped his useless wheel for a new one and carried on to finish 45th and dead last, more than 14 minutes behind the winner, Hamish Carter. 

By the time he reached the finish line, news of his actions had spread and Jenkins received a rapturous standing ovation.

For many his decision to carry on in the midst of adversity embodied the Olympic values of excellence, friendship and respect.

Among those watching from the sidelines was Helen Tucker, Jenkins’ then 20-year-old girlfriend who was in her first year of senior triathlon racing having finished fifth at the junior World Championships in Queenstown, New Zealand in 2003.

"It was hard," she recalls, "because I knew how much effort Marc had put in.  But I was pleased he finished."

Today, six years on, Tucker is Jenkins - they married in October 2008 - and all eyes are on her, not him, as she hopes to regain, and maintain, the form that helped her win the World Championships in Vancouver in June 2008.

Back then Jenkins was elated having lost much of 2006 and 2007 to injury.  But she couldn’t sustain her World winning form in Beijing two months later finishing a disappointing 21st.

"For me even qualifying for Beijing was hard," she says. "I think I just ran out of steam.  I didn’t have the endurance. I didn’t have anything on the day."

Jenkins will be hoping the tank is full to over-flowing for her next big race in her 2010 calendar, the London leg of the Triathlon ITU World Championship Series which takes place in Hyde Park tomorrow (July 24) and Sunday (July 25).

Like all races in the Series the Hyde Park event is over the Olympic distances of a 1500 metre swim, followed by a 40 kilometres bike and ending with a 10km run.  The swim will be in the Serpentine while the bike and run uses roads within the Park.

The elite women’s race will be held tomorrow and the men’s elite race on Sunday.  In between the two elite races are age-group, junior and paratriathlon events.

In total 3,000 age groupers are expected to take part, more than double the number in 2009, the first year the race was held.

London is the fifth in a series of seven races pitting the world’s best triathletes against each other in destinations around the world before a Grand Final in Budapest in September.

Jenkins, 26,  currently lies sixth in the rankings and is the highest placed Briton thanks to a 15th  place finish in Sydney,  ninth in Seoul and third in Madrid last month.

"Hyde Park is one of my big aims for 2010," says Jenkins who would like to equal, or better, her third place in the capital last year.

"I’d love to be on the podium," she says. "It’s always nice to do well in front of a home crowd."

The race is set to attract many of the world’s top triathletes not least because while it’s not an exact replica of the course being used at London in 2012 it’s fast and flat and gives Jenkins, and fellow competitors, a taste of what to expect in two years time.

"It’s good to get a feel of the venue a few years out," she says although Jenkins believes the London course has its limitations. "It’s not the most exciting course.

"There are no hills to break it up," she explains which will mean tactics will differ from courses, like Beijing and Athens, both of which were more undulating.

"It’s not a physically demanding course on the scale of the last couple of Olympics. Athens was very demanding; Beijing was quite demanding but there’s nothing at London that will put an extra strain on you."

When it comes to feeling the strain one area that’s not likely to happen for Jenkins is in the swim.

Born in Elgin, Scotland, her parents moved to Llantwit Major, South Glamorgan in Wales when Jenkins was four.  It was here she learned her love of water and was soon an accomplished swimmer.

"I wanted to be good swimmer," she says. "But it’s a really hard sport and by the time I was 15 I knew I wasn’t going to make it at the top level.

"I wasn’t quite making the national qualifying times," she recalls.

Switching to triathlon, a sport her father had competed in while future husband, Marc, trained at the same swimming club, seemed a natural transition.

After winning her very first triathlon Jenkins was promptly identified as a future talent and duly picked to race in France.

"I was rubbish," she says. "That could have put me off or motivated me and it really motivated me. They were good athletes in France and I thought I wanted to be as good as them."

By the time Jenkins had completed her A-levels in PE, Chemistry and Biology she knew what she wanted to do even though a career in nursing had seemed tempting.

"I started to earn money as a triathlete," she says. "It was hard to turn my back on it.  I wanted to do nursing but it would have been really full on and I don’t think I could have started that and trained full time as well."

With a weekly training log of between 25 and 30km in the pool, upwards of 160 miles on the bike and between 40 and 50 miles out running you can see her point.

Instead she’s been able to train full time thanks to the support of GE Capital, a subsidiary of GE, who are sponsoring both Helen and Marc, who’s now her coach, in the run up to 2012.

GE has also recently become the Elite Team Partner of the British Triathlon Federation.

Sponsorship aside there’s one area of training and racing Jenkins is unlikely to escape from the spotlight and that’s the weight of expectation British Triathlon is under having promised, and failed, to deliver a medal of any colour in either men’s or women’s races at successive Olympics since the sport joined the Olympic programme in 2000.

"I don’t feel the pressure of the past, I think the programme does," says Jenkins who was only 16 at the time of the Sydney Games when Britain’s Simon Lessing was heralded as near certainty for gold on triathlon’s greatest Olympic day. 

Lessing finished ninth and a decade on the wait for a medal goes on. 

"The public always have an expectation," she says. "I think what they don’t get in triathlon is that someone could knock you in the first 100 metres of the swim and your race could be over.

"There are," she adds, "a lot of uncontrollables."

For a start there’s the selection process. While Jenkins, along with Hollie Avil - who also raced in Beijing in 2008 - will be among the favourites for 2012 there are plenty waiting in the wings.

"There are some really good young girls coming through like Vicky Holland and Jodie Stimpson," she says, "as well as more established girls like Liz Blatchford and Hollie."

By the time London 2012 comes around Jenkins will be 28, the perfect age for an endurance athlete although she hasn’t ruled out the very real possibility of carrying on to Rio in 2016.

And were that to happen it would mean the name of Jenkins appearing on the start list of every Olympic triathlon since 2004 which would be quite a feat.

Indestructible back wheels should have come a long way by then.

Cathy Wood was editor of the Daily Mail Ski Magazine before moving to become ski correspondent on the Daily Mail. She later became travel editor before going freelance. She represented Great Britain at elite level triathlon and writes on travel, skiing and sport.