Watch: Bradley Wiggins makes 'schoolboy error' to place 21st in rowing championships (video)

Sir Bradley Wiggins placed 21st in his category at the 2017 British Indoor Rowing Championships at the Lee Valley Velopark in London on Saturday, after making what he called a 'schoolboy error'.

The 2012 Tour de France champion and eight-time Olympic medallist was taking part in his first major rowing competition since making the switch from cycling, aiming for a good result in the men's open 2000m distance.

As the 37-year-old started his effort on the static indoor rowing machine, he thought he heard someone say he'd made a false start, so eased up – only to realise that he hadn't.

Despite then trying to catch up on his pace, Wiggins could not make up for the lost time and finished 'disappointed' at the result.

"Huge disappointment today!" wrote Wiggins on Twitter. "Upon hearing a call in the background, I thought the race had false started so I put my oar down. School boy error but hey we live & learn as my plan was 6.02. Fantastic experience racing with everyone, will come back 12 months stronger next year!"

Adam Neill won Wiggins' category with a time of 5-48.2 to the former cyclist's 6-22.5.

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Wiggins has been coached by former Olympic rower James Cracknell, who said after Wiggins's disappointment that she should not give up and walk away from rowing.

"That kind of mistake will get in your head," Cracknell told Telegraph Sport of Wiggins's performance.

"You saw that the experienced guys just carried on. It’s a similar thing to the Boat Race. If there’s a clash, you don’t stop unless the other boat stops. Brad had been looking very strong in the first 500m."

Wiggins has previously said that he may try and aim for selection by British Rowing for the 2020 Olympic Games in Tokyo.