The 39-year-old came second in the men's road cycling time trial in Sydney on Sunday and celebrated by bringing his young son onto the podium with him.

It was an extraordinary moment but he says it was a long road to get there.

During his 20 years in the army, which included tours in Malaysia, East Timor, the Sinai and Afghanistan, Grover suffered a number of injuries.

When he discharged in 2016, Invictus became his next goal.

"It's sort of the end state of your training, as you get through your rehabilitation it's like the final goal you want to get to," he told AAP.

"And then to win a medal on top of that is even better."

Finding out he had placed second was a shock to the former infantryman.

"I thought I didn't do too well because my pedal clipped on the corner and I would have lost a few seconds there," he said.

"It's a real strong riders course ... because it's an all-out time trial it makes it hard for everyone to go as hard as you can."

Grover was cautiously optimistic when organisers told him he'd "unofficially" scored the silver medal spot.

"I said OK, we'll wait and see what happens - I've been popped off quite a few times," he laughed.

"When I found out it was true I was just stoked, it was great to know. I called the wife and said, 'Hey, where are you? You've got to get down to the podium and bring Nick', so they started running."

Grover's silver is one of two the Australian team has won in the cycling, with Emily Mysko also taking silver in the women's road cycling IRB2 time trial.

Australian Associated Press