The Catholic church was being discussed on the radio the other day when the presenter John Humphrys posed an interesting question: if any other organisation behaved so eccentrically and was embroiled in the same scandals, wouldn't it be utterly discredited or even closed down?

The same could be said for the Tour de France, which this summer will be contested for the 100th time. Right from the start, the world's most famous bicycle race has been mired in controversy. In its first year, 1903, the winner Maurice Garin smashed up his main rival's bike and then slipped him cash to keep it quiet. The following year, riders were spotted taking lifts from their support vehicles; eventually the top four finishers were all disqualified for "violation of the rules". Fast-forward a century and little appears to have changed: Lance Armstrong is the villain now, and there are seven blank spaces in the history books where his triumphs were once recorded.

So what explains our enduring fascination with this most transgressive of sports events? A new collection of stories and photographs, entitled Tour de France, provides some clues. There are vivid accounts and spectacular images of unwashed heroism on every page: from the early days when competitors wore ribbed pullovers, with their spare tyres lassoed over their shoulders, to the modern superstar athletes wearing Lycra now but climbing the same mountains on machines not so different from those the original pioneers rode.

Possibly the greatest tale comes from 1913, a race so gruelling that only 25 of the 140 starters made it to the finish in Paris. One of the favourites was Eugène Christophe, and he was well placed in the Pyrenees when the forks of his bicycle broke on the descent of the Col du Tourmalet. Others might have abandoned, but Christophe picked up his bike, trotted eight miles down the mountain and found a forge in Sainte-Marie-de-Campan where he – a one-time locksmith – fixed the forks himself. Afterwards he was asked why he chose to continue: "For the team, for the race…" he replied.

The book is compèred by Serge Laget, one of France's great sports journalists, a veteran of a quarter-century of Tours. Many photographs come from his collection. "My favourite picture is from the start line in Grenoble in 1909," says Laget. "I bought it 20 years ago at a great Parisian bookshop called Le Sportsman. It was taken at 2am on 15 July, and a photographer has caught the racers setting off under the stars. The moon is out, but streetlights are non- existent. They have to swallow up 345km to get to Nice: that's 12 hours in the saddle for the best of them, 18 for the stragglers. In one image, the age of heroes is evoked."

There are iconic photographs of all the greats: Fausto Coppi, Jacques Anquetil, Eddy Merckx and Miguel Indurain. But when Laget is asked to pick one rider who best sums up the spirit of the Tour de France, he selects someone who never won the race: Raymond Poulidor, "Poupou", who finished second or third on eight occasions. "Because of his talent, courage and perseverance, Poulidor has become one of the great figures of the Tour," says Laget. "But it is the crowning achievement for any cyclist to finish the race in Paris. Those that do join an elite group: 'the Giants of the Road'. Since 1903, there have been only 3,095."

Looking back over 99 editions of the race, it is gratifying to realise that the same features that first made it popular are still present today. It remains completely free and unfailingly dramatic – whether you are watching the racing or just gazing at the scenery. The 100th race looks set to be an intriguing addition to the canon: can Bradley Wiggins win his second Tour? Or will his Sky team-mate Chris Froome claim his first? But, as always, there is as much intrigue off the bicycle as on it: can we believe the feats we are watching?

"The French, affected by the Armstrong case, are still a bit wary of the exploits of Team Sky and Wiggins," admits Laget. "Another win this year by Wiggins would help to settle our unease and, if he helps Froome to win, that would be nice, too. The spectators love this rivalry. Long live Britain: bringing us a breath of fresh air to dissipate the noxious influence of Armstrong. Let's dream!"

The Tour de France Official 100th Race Anniversary Edition is published on 18 April by Quercus at £30. To order a copy for £24, with free UK p&p, click on the link or call 0330 333 6846