By Nigel Wynn
Allegations that pro riders are using motors in their bikes during races have been resurrected after video footage emerged on the internet purporting to show Ryder Hesjedal's bike moving by itself after he crashed on stage seven of the Vuelta a Espana.
The Garmin-Sharp rider crashed on a corner whilst in an escape group on Friday's stage seven. As his bike falls to the road, it appears to start moving on its own accord before being run over by a motorbike.
This has prompted several media websites, including that of respected French newspaper L'Equipe, to ask whether the bike is motorised.
From the clip it's impossible to tell the gradient of the road, and the motion of the bike could simply be explained by it slipping down the road. Commercially available motors in bicycles will also cause the chainset to rotate to drive the wheel, since the motor is in the bottom bracket - which is clearly not the case in this clip.
Claims of motors being used by professional riders first came to the fore in 2010, when Fabian Cancellara was accused of having a motor hidden in his bike to win the Tour of Flanders and Paris-Roubaix.
Italian former pro Davide Cassani has claimed that such bikes have existed - and been used - since 2004, and demonstrated a bike containing a hidden motor to Rai Television (see below).
Professional cycling's governing body, the Union Cycliste Internationale (UCI), now regularly uses X-ray machines to scan bikes at events to detect hidden motors. As far as we know, they have never found one.
Update: Garmin-Sharp boss Jonathan Vaughters gives his explanation:
Internet video clip of Garmin rider Ryder Hesjedal’s stage seven Vuelta crash led to stories of his ‘motorised’ Cervelo
Swiss rider Fabian Cancellara starts at the Tour de Suisse on Saturday and dismisses motorised bike rumours
Former Italian rider says that motorised bikes have been used in the pro peloton since 2004
Allegations of 'motorised doping' using concealed on-bike electric motors come under scrutiny