Today's stage, which covered some of the road of Paris-Roubaix, was always going to cause panic and consternation amongst the general classification favourites. It's not often you see small little climbers tackling the Hell of the North, and from memory, Bernard Hinault is the last Tour winner who also won Paris Roubaix.
In the wet, the cobbles are slick and greasy, but in the dry they're still slippy, uneven, and very difficult to ride over. If you've never ridden pavé it's perhaps difficult to describe, but essentially it's very jarring, and shakes you all over your body. Everywhere aches. At the end of such a large amount of pavé it'll feel like the fillings in your teeth are about to drop out, you'll probably have a headache, and lots of joints and bones can ache after being literally battered over the cobbles. Add on to that dry, dusty roads and it'll feel like you've been inhaling a cloud of mud and dirt. In short they're pretty much no fun whatsoever.
Of course, riding the cobbles well is a skilful task, and that's why anyone with aspirations of doing well overall had reconnoitred the course before hand. In an interview with Alberto Contador, he said that he'd been training over the cobbles with ex-rider Peter Van Petegem, who was very adept at riding cobbles and the northern classics. I suspect that Fabian Cancellara had given a master class to the Schleck brothers as well, although Frank crashed badly today and has withdrawn from the Tour.
How do you ride the cobbles? Well firstly to ride them well, you need to start at the front so that you're less likely to be caught in a crash, and also so you can see where you're going and so that you can dictate the pace. However, these are narrow French and Belgian roads, and everyone who wants to do well wants to be at the front. So, this is similar to delivering the GC contenders to the base of a mountain pass at the front. It means the pace will be very high with riders riding at high power to keep their team leader near the front and stop others from coming to the front. The Saxo Bank team executed this nearly perfectly.
Once on the cobbles you'll see the leading riders in each group searching for the smoothest bit of road possible. Usually this is the gutter and allows the riders to get away from the jarring cobbles. If the riders bunch up then most of the riders will be forced onto the main part of the cobbles. This requires good balance, and an ability to withstand the jarring pain. The centre of the road is usually slightly higher than the sides and this means the riders can slide easily causing crashes. To counter this, rather than being bunched up the riders will try to ride single file in the gutter, but this isn't always possible.
If you do crash, it's likely going to be a worse crash than on normal roads. Riders behind have less chance of stopping both due to the slippy nature of the cobbles, and also due to reduced visibility from the dust clouds.
Finally, in terms of today's race Thor Hushovd rode a brilliant race, rarely going to the front and then sprinting perfectly for the stage win. Both Hushovd and Geraint Thomas did no turns on the front to protect their team leaders (Carlos Sastre and Bradley Wiggins respectively) as had Hushovd or Thomas helped the Saxo Bank pairing they would have contributed to a bigger lead for Andy Schleck over Sastre and Wiggins.
Psychologically, you're going to have to be brave to ride well over the cobbles and not fear them. Worrying about them is likely going to make you tense up and not ride smoothly, which in turn will make you more like to crash. As with most things, practice makes perfect, so search out some cobbles near you and try riding them.
Power wise, the riders were likely pounding out about 500W as they went through and off as they fight for position before the cobbled sectors. Joe Average would be dropped before the cobbled sectors and without proper practice would likely crash if they hit the cobbles at the speed the pros do.
Here's hoping that Stage 4 is less incident packed with no or very few crashes and a good sprinters battle between Ale Jet, Hushovd, and Cav.
Ric Stern (www.cyclecoach.com) is a full time British ABCC coach. During this year's Tour de France, he will be providing a physiological insight into the challenges that face the riders in each stage.