CYCLING TOUR DE FRANCE:WITH LIGHTWEIGHT wheels, €10,000 bikes and hi-tech training methods, cycling is a modern sport, but is also one influenced by deep-seated tradition and customs. One of its longest-running unwritten rules appeared to have been broken yesterday and, as a result, debate raged long after the dust settled on the finish of yesterday's Tour de France stage in Bagneres-de-Luchon, won by France's Thomas Voeckler.

The controversy erupted when maillot jaune Andy Schleck attacked close to the summit of the day’s final climb, the steep ascent of Port des Balès. Schleck needed to gain time over his closest rival, Alberto Contador, as he is expected to lose up to two minutes in next Saturday’s concluding time trial.

A strong acceleration from midway down the leading group caught the Spaniard unawares, but, just as Schleck was pulling farther ahead, his chain dropped off and he skidded to a sudden halt.

Contador, Samuel Sanchez (Euskaltel Euskadi) and Denis Menchov (Rabobank), who started the day second, third and fourth overall, whipped past the stricken Saxo Bank rider and continued to drive the pace when it became clear Schleck had a mechanical problem.

The latter got the issue sorted and set off in pursuit, but was unable to close on the long descent to the finish and came home 39 seconds back.

The effect was he lost yellow to Contador by eight seconds, with the Astana rider taking the jersey to a mixture of cheers and boos.

“Now I’m really angry,” said a grim, gutted Schleck. “I will ride on the Tourmalet until I fall from my bike and give everything to this race.

“I felt really good, but what counted at the end of the day is the time that you have when you arrive at the finish. I was so far back even with what I did on the descent (taking risks).”

Contador admitted he understood Schleck’s disappointment, but insisted he did nothing wrong.

“I didn’t know anything about the problems with Andy Schleck, but when I realised it, I was already ahead of him,” he said. “The only thing that I saw was that he was beginning to attack and then he slowed down. I didn’t realise that he had a problem with the bike.”

Nicolas Roche was also caught out on the climb, due to a front wheel puncture 28km from the finish. He was hampered by a slow wheel change, and then from a lack of support from his Ag2r La Mondiale team-mate John Gadret.

Gadret was also in the shrinking peloton, but rather than dropping back to help his team leader, he attacked at least twice on the climb.

This helped stir up an already aggressive situation and Roche never managed to regain that group. The 26-year-old chased hard but eventually finished 37th on the stage, nearly eight minutes behind Voeckler.

This saw him drop from 14th to 17th overall, and end the stage extremely frustrated by what had happened.

Finishing in the top 15 overall was a major goal for him, but he now faces a fight in the days ahead. It’s still possible, but everything will have to go exactly to plan, and that includes team support.

Amid the hullabaloo yesterday, a stirring stage victory by Voeckler was a little forgotten. The French national champion continued the excellent winning streak by home riders, netting the fifth success of the race when he soloed in.

He had been part of a 10-man move which went clear almost 90km into the stage, and which built their lead on the climb of the Col de Portet d’Aspet.

This mountain is enshrined in Tour history as the location where Olympic champion Fabio Casartelli crashed and lost his life in 1995.

Voeckler later made his stage-winning bid when he jumped clear seven kilometres from the thronged summit of the Port des Balès, and eventually hit the line one minute 20 seconds ahead of Alessandro Ballan (BMC Racing Team) and Aitor Perez Arrieta (Footon-Servetto).

Two more days remain in the high mountains: today’s race to Pau, which crosses several tough climbs early on but has a flatter run to the finish, and Thursday’s gruelling, three-peak epic to the top of the Col du Tourmalet.

The yellow jersey battle will rage even brighter now, with Contador sure to come under attack. He is a better time trialist than Schleck, who needs to exit the Pyrenees back in yellow, and with a strong buffer in time.

To do that, he’s going to have to channel his anger and frustration into speed.

“I’m sure he will attack me and I always have fear of what he might be able to do,” admitted Contador, who until now has appeared to be at the same level as his rival on the climbs, while being less dominant than 12 months ago.