'No matter what, he will attack. Alberto Contador will attack until he can't pedal any more'

Spaniard Alberto Contador, who celebrated his 34th birthday this week, may be the oldest of the current Grand Tour stars, but insiders say “it’s guaranteed he will attack” to explode race order.

Contador posted a message to his fans on Twitter and Instagram. The bearded cyclist from Madrid, so fit and trim ahead of what could be his final season, seemingly disappeared behind the cake.

"It's what sets Alberto apart, his will to win no matter what setbacks he's had," Sean Yates told Cycling Weekly.

"We saw that in the Tour de France last year. He finished fifth after winning the Giro d'Italia and he was terribly, nasty empty, but he still finished fifth and wanted to attack and [was] trying to attack.

"No matter what, he will attack. It's guaranteed with Alberto Contador, he will attack until he can't pedal anymore."

Yates directed the Tinkoff team at the Vuelta a España this summer with Contador as leader. In the third week, Contador attacked only six kilometres into the short 118.5-kilometre Formigal stage and ruined Chris Froome's chances of winning the Vuelta title.

Contador, already too far back in time for the win, fought for a podium place and helped Nairo Quintana (Movistar) ride away to secure his eventual overall title. Froome, isolated immediately, lost 2-43 minutes.

Contador already counts three Vuelta a España titles, two from the Giro d'Italia and two from the Tour de France. Had they not been stripped for a doping case, he would have one more each from the Giro and Tour – nine in total.

Trek-Segafredo signed Contador for his attacking spirit and experience. He will lead its Tour de France team and help Bauke Mollema improve in 2017.

"He has plenty of experience," Trek-Segafredo General Manager Luca Guercilena said. "Clearly, he needs it going up against Froome. But he's won three tours and that experience will help him when the race is stressed.

"It's clear that he's getting older and that's always a limiter, but athletes like Alberto can find resources when needed. Many people wrote off Fabian Cancellara, called him finished, but he found what he needed to win [the Olympic time trial]. You can experience your resources better when you are older."

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That race knowledge and know-how won Contador the 2012 Vuelta. He toppled race leader Joaquím Rodríguez in a mid-stage attack instead of waiting until the final kilometres of a summit finish stage.

Contador's attacks blow fresh air through the Grand Tours often controlled by the iron-grip tactics of teams like Sky and Astana.

Yates said that is exactly what the Tour missed this July when Contador abandoned after one week due to crashes in the first two stages.

Yates also worked for Team Sky and directed Bradley Wiggins to his 2012 Tour title.

"In recent times, we've seen teams like Sky control, it matters much more," added Yates. "So his style of riding is coming less effective and he has to use his energy more wisely.

"And ultimately a lot of these big Grand Tours are won in time trials, and Froome is great in time trials. Contador though is a tough cookie."

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In Grand Tour stage races, Contador is the oldest of the top stars. Froome is three years younger at 31. Quintana is 26 years old and Vincenzo Nibali (Astana) is 32.

"Contador is the best rider after [Eddy] Merckx, at stage racing at least," Sean Kelly told The Telegraph. "He's a rider that will always do something. In the big tours he will attack at some time and I think that is just great for cycling.

"When you look at the guys winning the Tour de France in the last 10 or 15 years it is very much calculated: they ride the race, they follow their team then they do the time trial, but Contador is always up for doing something."