The 34 year old took his hand off his handlebars to blow his nose when a gust of wind caught his front wheel and sent him careering into a wall at 54kmh (33mph) in France on Wednesday.
He was airlifted to Saint Etienne University Hospital for surgery after fracturing his femur and breaking his hip, elbow and ribs.
Speaking to BBC Radio 5 Live’s BeSpoke podcast, Sir Dave described the accident as a “bad crash”.
He said: “He came down the descent, which was quite a technical descent, then he came into a straighter piece of road with housing either side.
“He was riding with Wout Poels at the time and he signalled to Wout that he was just going to blow his nose, you know how they put their finger on the side of one nostril just to clear the nose.
“He took his hand off the bar to do that and a gust of wind took his front wheel and he lost control and went straight into the wall of a house.
“He’s not in great shape. He’s in intensive care in Saint Etienne hospital now.”
Teammate Wout Poels was accompanying Froome on a practice ride ahead of stage four of the Criterium du Dauphine in Roanne, France, when the accident happened on Wednesday.
He initially estimated they were travelling at about 65kmh, but Sir Dave said Froome’s Garmin data revealed that “he went from 54kmh to a dead stop”.
Sir Dave said it was an “evolving situation” and that the four-time Tour de France champion’s wife Michelle has been flown out to be at his bedside.
“Time is of the essence in these situations,” he said. “He’s been operated on to make sure that first phase of medical care is as optimal as possible.”
He added: “We see crashes every day but there’s crashes and there’s bad crashes and I think this is a bad crash."
Froome has now been ruled out of competing in the Tour in Brussels next month.
Team boss Sir Dave said he will now have to “channel everything he has got into his recovery”.
He added: “He’s just come back from Tenerife, I’ve seen how hard he’s worked, I’ve seen the amount of sacrifice and effort he’s put into trying to win that Tour this year and he was really on track, he was in really good shape here and he was just going to put the finally touches on his condition and go for the Tour again.
“I’m sure we’ll see him back racing again.”
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