Fabio Aru's crash during stage 17 of the Vuelta a Espana was apparently sparked by a blocked chain, with the UAE Team Emirates rider losing control of his bike at 70kph as he tried to pull his chain back onto the 12 sprocket.
Aru landed on his back and seemed stunned after the crash. When he got up he vented his anger by shouting repeatedly about his bike to his UAE Team Emirates staff and said the gears had locked up. He eventually got going again on a new bike and finished the stage with his shorts in shreds.
The Italian suffered road rash and took a blow to his back, but he is set to continue in the Vuelta as he tries to fight through the disappointment of his season and secure a place in the Italian team for the World Championships in Innsbruck.
"His chain got stuck on the 11 sprocket and he pulled it with his hand to try to release it and put it on the 12 sprocket. While looking down, at 70kph, he crashed," UAE Team Emirates team manager Matxin Fernandez told La Gazzetta dello Sport.
"It wasn't nice to see but it was a gut reaction. He went down at speed, with his heart beating at 200. He was scared. I understand him. What would any other person have said?"
Colnago also revealed that he had a long telephone conversation with Aru on Wednesday evening.
"I've provided bikes to thousands of riders but I've never been insulted live on television like that. At least he called and apologised for 15 minutes," Colnago told La Gazzetta dello Sport.
"I can understand that he's having a difficult season and everything is going wrong. But I explained that he's a professional and that things will go his way eventually. I don't understand what happened. If the gears blocked he wouldn't have crashed, he'd have locked up, not crashed. The bike isn't at fault."
UAE Team Emirates published Aru's apology for his strong words. He explained his reaction was due to a sense of fear. He admitted the crash was sparked by a "moment of distraction."
"My reaction was a little too aggressive but that's because of the shock and because my back hurt a lot," Aru told La Gazzetta dello Sport.
"Fortunately I'm okay. I've got some road rash on my glutes and back but it could have been a lot worse. Crashing at 70km/h is never nice."
After treatment by the UAE Team Emirates doctor, Aru was given the green light to continue in the Vuelta.
"The goal is to finish this Vuelta. As I'm not a GC contender anymore, I'll focus solely on getting ready for the World Championships. If I feel good and if I'm not too beaten up, the final mountain stages could be interesting," he said.