questione di leve? Vincenzo Nibali al Giro 2016

Avevo raccolto l’analisi di Paolo Bettini prima della riscossa di Vincenzo Nibali e ora osservo quella di Michele Ferrari a fine Giro 2016 (2000 battute in potabile inglese) …

A dozen years ago, Eddy Mazzoleni, a rider of similar size (181cm x 67kg) to Vincenzo Nibali, decided to increase the length of his bike cranks from 172.5mm to 175mm. He showed up to a training camp on Mt. Teide with this change already being adopted by a few weeks. Despite the good feelings on the bike, the performance during the longer sessions showed conspicuous declines in the final, seemingly without a specific reason related to nutrition or otherwise.

Longer cranks allow a greater thrust lever, reducing, at the same wattage, the peak force required in pedaling, but it forces the legs to a wider revolution. This leads to changes in joint excursions, higher internal friction, resulting in greater energy expenditure, which in prolonged efforts results in a drop in performance over the long distance.

For the record, after a few days of obvious difficulty, I suggested Eddy to switch back to 172.5mm: he immediately felt at ease and performed at his usual best. I believe that the difficulties of Vincenzo Nibali in this Giro, his unexplained drops in performance, in addition to the inevitable psychological repercussions, both depended on the wrong choice to adopt longer cranks.

And I think, albeit without absolute certainty, that his “miraculous” and spectacular recovery in the last two alpine stages was due to a providential return to 172.5mm cranks, facilitating his higher pedaling cadences on the climbs. The technical level of this 2016 edition of the Giro, despite the spectacular epilogue in the Alps, was not very high.

The power outputs expressed on the climbs rarely exceeded 6.00W/kg: even Steven Kruijswijk, the unlucky revelation of this Giro, in the uphill time trial in Siusi (10.8km at 7.3%) expressed a VAM of 1646m/h = 6.09W/kg .

Even the best Nibali during the crucial stage to S. Anna di Vinadio never really delivered wattages higher than 6.00W/kg in his decisive attack on the Col de la Lombarde. Esteban Chavez deservedly got second on the final podium, whereas the white lips of Alejandro Valverde confirmed his difficulties at altitudes above 2000m.