Part of the reason the Tour de France has charmed generation after generation for more than 100 years, seducing people who don't give a flip about cycling, converting some of them into permanent spoke-heads, is simple.
The Tour is open. Most of the course is free of barricades. No tickets, no exorbitant parking, no luxury boxes. All it takes to be part of it is whatever effort you want to put into getting there and setting up your folding chairs and your picnic table.
Fans can walk right up to the top-heavy rolling locker rooms called team buses at the finish and plant themselves in a rider's path when he wheels in still lathered in sweat from covering more than 100 grueling miles. If he doesn't run you over, he might sign an autograph or hand over his plastic water bottle.
Tour reporters get books listing the names, addresses and phone numbers of team hotels, and when you walk in (they're rarely secured), there's usually a rooming list posted on a wall in the lobby. Imagine the Dallas Cowboys or San Francisco Giants doing that. It's either quaint or really, really dumb.
Spectators routinely run alongside top riders who are grinding up mountain switchbacks and slap them on the back or pour water over their heads. On rare occasions, a flag-waving, overly enthusiastic fan inadvertently brings a rider down.
More often, the riders bring themselves down, and the very openness that makes bike racing so unique ensures that the ugly side of the sport will be unusually exposed as well.
Professional cycling is conducted in public spaces. It's chaotic and edgy, thrilling and petty, full of arcane etiquette, rife with ego and political infighting, and often dysfunctional -- never more so than in the last 48 hours.
Alexandre Vinokourov, who swept into his pre-Tour press conference in London with the entitled look of athletic royalty, and his Astana team were exiled Tuesday because of his initial positive test for a banned blood transfusion.
In a sad and moving moment that afternoon, David Millar, one of the few riders to confess to doping and come back from his suspension with a fierce, outspoken passion to do the right thing, broke down in tears at the news of Vinokourov's apparent indiscretion.
The next morning, high in the Pyrenees, a small bomb allegedly planted by the Basque separatist group ETA exploded harmlessly in the woods alongside the Stage 16 course. That was only part of what should go down as one of the most bizarre days in the history of this or any other major sporting event.
It dawned with some riders refusing to roll past the start line in Orthez, France. They leaned on their bikes in a symbolic anti-doping protest against, well, themselves, we're guessing, because doping comes down to an individual decision made in private.
The standing protest was poorly organized, a hallmark of most group endeavors in cycling, from business meetings to bunch sprints. So after an indeterminate amount of time, perhaps 10 minutes, the front of the peloton pedaled away. Fans reacted uncertainly, then caught on that not everyone was moving. Scattered booing erupted.
Riders behind the protestors got impatient and began squeezing through one at a time like workers crossing a picket line. They were booed too. Then everyone finally got rolling, including one member of a team advocating clean sport who was busted later in the day for a positive testosterone test.
The rider in question, Cristian Moreni, was met at the finish line by unsmiling representatives of the French National Police, who escorted him off the Col d'Aubisque.
In recent years, the criminal justice systems of various countries have become honorary members of the peloton in their quest to find dopers. Their actions frequently take place out on the open road for all to see, just like the race.
Astana's bus and three others were pulled over and searched alongside a toll booth on a major highway one day this week -- the same toll booth hundreds of journalists were then passing through on their way to the finish line that day. It was only natural that a few of them got out and shot pictures and took notes.
When the news of erstwhile race leader Michael Rasmussen's final fall from grace hit these same reporters' BlackBerry devices and cell phones, there was a mad rush to the Rabobank team hotel in Pau, made possible by the fact that we all had a book telling us exactly where it was.
Rasmussen was undone by a failure to be open. He lied to his employer about where he was -- an act cycling can't afford, since its workplace is any road in the world, and the workers have to be accountable to anti-doping authorities for testing at any time.
Of course, Rasmussen's demise underscores the fact that cycling is open only in a superficial sense. Its doping culture is a dense web of secrets, and riders have become so accustomed to it that obfuscating is the norm, fibbing is habit, and cheating is common currency.
T-Mobile team manager Bob Stapleton, as capable and well-intentioned a person as there is in this sport, said earlier this year that the fight against doping would not be won on the basis of doping tests alone. He said it would take the ability to suspend or fire or prosecute riders on the basis of circumstantial evidence, or at least something less tangible than a beaker of urine or blood.
Rabobank turned the other cheek when Rasmussen went missing for three weeks in June and didn't punish him until he was under the microscope in the Tour leader's yellow jersey and events compelled it. The team's acquiescence to the old see-no-evil philosophy has brought embarrassment and scorn raining down on them in a way that will be hard to reverse. Perhaps that will be one of the first positive deterrents that isn't a positive drug test.
There is still a lot going on underneath the surface in the most open professional sport on the planet. The people who want to change cycling for the better are still cracking the codes and trying to see through the tinted windows on the big team buses.
If doping scandals make you doubt that the physical feats you see in a bike race are real, look again. Look at the whole sport. It's convulsing in a very real, human, imperfect way. Things may get worse before they get better, though it's hard to imagine how much worse they could be than they were this week at the Tour de France.
Bonnie DeSimone is a frequent contributor to ESPN.com.