After a gruelling expedition traversing the French - and, briefly, Italian - countryside, 167 riders were left standing at the end of the 2011 Tour de France. The comparatively leisurely roll along sweeping Parisian streets was completed on Sunday, ending the two-wheeled marathon after 23 days, 3429 kilometers, and two intimidating mountain ranges.

It has been dubbed as one of the greatest tours in recent memory. It was certainly one of the most different.

Since 1967, the Tour has almost always begun with a short time trial, or prologue, to ease the riders into the rest of the tortuous campaign.

From the very first morning, 2011 was a different year for the Tour, but not just because of the different starting route.

For the first time in what seems like an eternity, the 2011 Tour seemed to be free from the effects of doping.

More than just about any other sport, cycling has suffered in reputation from rampant drug use. Since the start of the 1990s, the majority of top-three finishers in Le Tour have either failed drug tests, openly confessed to drug use or been connected to prominent investigations.

Floyd Landis, Alberto Contador and Lance Armstrong are the poster-boys for this damaging trend in the sport. Landis was infamously stripped of his 2006 title; Contador is under investigation and is at risk of suffering the same fate as Landis with his 2010 crown.

And ever since Armstrong won his first of seven Tour de France championships in 1999, he has constantly been the subject of doping allegations.

The Tour resultantly lost much of its credibility in the eyes of its public.

Cycling as a whole was dangerously close to becoming a laughing stock.

As the saying goes, desperate times call for desperate measures.

In 2008, cycling implemented one of the most attacking and reforming strategies in the history of sports: the biological passport. The passport does not primarily aim to detect illegal substances in riders, but instead it sets out to find the masking substances used in doping.

The passport is an incredibly strenuous and invasive level of testing for cyclists, given that the athletes have to be available and accessible for testing all year-around.

But the rigorous regime appears to be having an effect: cycling's proverbial war against drugs is being won.

The most telling sign came in the form of a slowing down in average times over recent years. The developing trend toward slower performances is blatantly clear to see, with the finishing climbs in the 2010 and 2011 Tours de France being significantly slower than those seen during the previous two decades.

But more specifically, the fastest riders on three of the last climbs in the Tour were three minutes slower than the majority of the fastest riders on the same climbs since the beginning of the 1990s.

Put simply, the times from the past two Tours are similar to those times recorded in 1989.

That year, 1989, is the significant date in the discussion of doping in cycling, as it was in 1990 that the drug EPO first hit the market. At the risk of sounding dangerously like a lab report, EPO produces more red-blood cells in the body, which then causes an increase in oxygen in the blood flow. More oxygen in the blood allows for more oxygen to be delivered to the muscles, which drastically increases performance.

Prior to about a decade ago, there was no method of testing for EPO. As a result cyclists were able to use EPO with impugnity, knowing they could not be caught.

After 2008, the passport has tightened the noose around the neck of any potential dopers.

EPO was seen as the prototypical substance that was at the forefront of the cycling doping epidemic. Eliminating the rampant use of EPO cleansed the sport, both in regards to its athletes and in the eyes of the public.

So as Cadel Evans crossed the finish line on the Champs Elysees in the early hours of Sunday morning it was not only a triumph for the Australian veteran, but it was also a victory for the sport of cycling.