Geraint Thomas auctioned off the Ineos Grenadier gilet he wore at the Tour de France on Monday.

The gilet was made famous during the first stage of the Tour de France in Copenhagen, when Thomas admitted he forgot to take it off during the 13.2km time trial.

Thomas, who won the 2018 Tour, was 18 seconds behind the lead group at the first time check.

The result was even more unexpected as he had been riding well, finishing second in the Tour de Suisse time trial and going on to win the overall.

Tomas, one of three Ineos GC leaders in this year's Tour along with Dani Martinez and Adam Yates, admitted that he forgot to take off his gilet and recorded a negative split.

"The first half of the time trial was the worst I've ever had. 'My wife hasn't been on a bike in 12 years. I realized I was wearing a gilet. I zipped it up and it was so snug, I didn't even notice."

Thomas improved his time in the second half of the time trial and finished 18th." The legs were good. That's the most important thing, but the cornering was terrible. I was overthinking things."

"I was just too busy thinking."

Thomas finished 18th in the time trial.

Thomas wrote on Instagram: yes, I'm done laughing at my gilet: ...... Thought I'd have some fun."

He is challenging himself to travel around France with the gilet, starting today in Dunkerque. I want to deliver this gilet to a different fan each day, and when it comes back to me in Paris, I want to auction it off and donate the proceeds to the Geraint Thomas Cycling Trust."

Thomas is currently in 12th place, 32 seconds behind yellow jersey winner Wout Van Aert (Jumbo Visma).