Thomas, just like in the Giro d'Italia, fell on stage nine. In the Giro d'Italia, he quit five days later after suffering with a sore shoulder and knee. He raced the Tour to help Chris Froome win and see how far he could go in the overall.
"It's a massive disappointment," he told VeloNews. "Just like at the Giro. It was stage nine as well. I was sitting second overall as well
"I don't know what it is for this year, it's just not happening."
Thomas fell four times in this Tour de France, on stages two, four, eight and nine. He broke his right collarbone this time, forcing him to abandon the race.
He was one of many to fall on stage nine, along with Rafal Majka (Bora-Hansgrohe), Robert Gesink (LottoNL-Jumbo) and Richie Porte (BMC Racing). Porte remains in the hospital.
He fell on the Col de la Biche descent that was slightly wet due to the day's rains.
"Majka just came down right in front of me, and I had nowhere to go," Thomas said.
"I knew something was wrong. Normally, you can just get up and get going again. You just have to accept it."
Thomas, known for his hardness, pushed on until down until he reached the valley, but he knew something was "bad" and it was confirmed by the team and race doctor.
His collarbone had broken, which usually means six weeks without racing. The Welshman came off lightly considering some of the other incidents, including the scary looking one with former team-mate Porte.
"I really hope Richie is OK, I saw a bit of that crash. It's not nice watching guys go down like that. I really hope he's OK.
"Where I crashed, I don't think it was [too dangerous]. I just don't know what Majka was doing.
"He was at the inside of me a few times on the corners, just desperate to get around me. I let him pass, and literally 10 seconds later, he's on the floor, taking me down, and [Matteo] Trentin as well."
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