Geoffrey Wheatcroft, the author of Le Tour - A History of the Tour de France, answers your e-mails.
The Tour is one of the most grueling sporting events ever created, covering distances of over 4000 kilometres, including heroic climbs through the Alps and the Pyrenees.
With horrific injuries, deaths and scandals all marring its history, Wheatcroft's Le Tour examines the continual draw of an epic race.
We put your best Tour questions to Geoffrey. Read on to see his replies.
The French sports paper "L'Equipe" has just published its "100 greatest riders of the Tour" list. It reads 1:Merckx, 2:Hinault, 3:Anquetil...7:Armstrong, 8:Indurain.
Do you think this disparity (excepting Merckx) is to do with French pride? Or did the top three champions really have more style and panache?
I personally think that Armstrong (who's clean, and whose comeback defeats all others), should be ahead of the clinical - and self-confessedly doped - Anquetil.
There is certainly a lot of French prejudice against Lance Armstrong. I saw it last year when they were screaming abuse at him on the road. But to say that Jacques Anquetil is dope-stained is - unfortunately - something you could say about many great riders.
The honest answer is that it's impossible to compare riders from different generations, although Armstrong should certainly be higher than seventh. That's just silly.
Who is your favourite rider?
If forced to pick one, I would have to agree that Merckx is the best. He was a great cyclist and a remarkable man. He also had to put up with a lot of prejudice because the French don't like the Belgians any more than they like the Americans.
If I had a personal favourite, it would be Gino Bartali. A splendid and brave man. He has the remarkable distinction of winning the Tour twice at 10-year intervals - in 1938 and '48.
Where would you rate Greg Lemond alongside the great winners? By only winning a mere three (!!) Tours he seems to be forgotten when comparisons are made, but I think he could have been even greater but for the cruel accident that curtailed his career.
Are there any others who you feel had the potential to join the elite group that is always discussed?
Another good point, although I don't think Lemond is as great as Armstrong. But I do think there are two Italians who belong in that elite group: Bartali and Fausto Coppi. Before the war it was a remarkable feat to win the race twice, let alone five times.
Nowadays bikes and training methods are much more advanced. Cyclists are much fitter, quite apart from any illicit substances they may be using. Although Bartali and Coppi only won the race twice each, they did so in circumstances as remarkable as anything in recent history.
Although Armstrong's ability is unquestionable do you believe that he has faced easier opposition than other multiple Tour winners.
Paul Aldridge, Birmingham
There is no doubt about that. Armstrong is a great cyclist but he has also had a great deal of luck. For a variety of reasons, over the years people who might have given Armstrong a race have simply failed to do so.
One thing the Tour has lacked in recent years, in this heyday of Armstrong's triumph, is the kind of great duels we saw before between Coppi and Bartali, or Anquetil and Raymond Poulidor. This has to be taken into consideration when assessing Armstrong's performance.
Can anyone provide competition this year?
I didn't think so at first but there have been signs. Armstrong only managed seventh in the Prologue, which was very surprising. He was also hurt in the huge pile-up at Meaux.
But in a way his luck continues to hold, because Tyler Hamilton, another American who I thought might have been a serious challenger, broke his collarbone in the pile-up and pulled out of the race (albeit temporarily).
In your opinion who was the best cyclist never to have won the Tour de France?
Nick Walker, Antrim, Northern Ireland
It would have to be Poulidor; the man who never won the Tour. He never even wore the yellow jersey. But his record of consistency - the number of times he was either second or third over a ten-year period - was extraordinary.
Many thought that it wasn't just down to bad luck and that he lacked the killer instinct. But I think he's the best rider never to win it.
Has the Tour lost some appeal due to the continuing problems surrounding drugs and stimulant taking and are the Tour organisers trying to gloss over all the scandals that have taken place since 1998?
Chris Price, Ireland
I don't think it's lost any appeal. You have to accept the fact that there has been a lot of doping over the years. The authorities used to be thoroughly negligent, but I think that's less true now. Everyone is praying that there won't be any major drug scandals this time around.
The Tour is one of the most gruelling physical events mankind has thought up. What is it that drives the athletes to mount their bicycles and take their bodies through over 3000km of hell?
Ryan Johnson, Ontario Canada
You tell me! I wouldn't do it. That's why I feel such an intense admiration for the cyclists. I cannot get my head around the feat of endurance that I witness as they climb such great passes and ride such distances. And they don't even do it for huge sums of money. They do it because they love it. They are real sportsmen - and gladiators.
Chris Boardman commented on Lance Armstrong being one of the "least liked" Tour winners ever. Who would you say were the most liked and least liked Tour riders over the years?
I think Anquetil wins the prize for being the least liked. Even when he was winning the race for France the French never took to him. He was a very cold fish indeed.
The most liked would probably be Ferdi Kubler, who won the Tour in 1950. He was a very charming and delightful man. Everybody liked him.
Why is it that there are never any English riders of any note in the Tour these days?
Mark Roberts, Shrewsbury
We've just never been any good at it. Just like we invented football, cricket and tennis and can't win anything, we also invented the bicycle. I wish we did do better, but there aren't any signs of a British revival.
What do you think has changed most about the Tour since it began?
Stuart Nisbett, West Sussex
There are three main things. Firstly, the condition of the roads has changed enormously. Secondly, the quality of the bikes is much better. They are far lighter and stronger. Thirdly, the cyclists have become much fitter. How they managed to get around in the old days was remarkable. They didn't train at all, they were just working men.
Which, in your opinion, has been the toughest stage for a majority of riders in the history of the Tour De France since its conception?
Andy Gbinigie, Manchester, UK
It would have to be any stage over the Col du Galibier. It's the most exhausting climb of the lot. The two or three great Alpine passes are always the toughest.