Carol Boardman sustained serious injuries after a collision with a pick-up truck as she was cycling in Connah's Quay, Flintshire, on Saturday.
She later died in hospital.
Ch Insp Darren Wareing said: "A full investigation is now under way, which will include a forensic examination of the scene, vehicle and bike.
"We have already spoken with a number of people, including the driver of the Mitsubishi pick-up, however I'd like to ask again if you were in the area at the time and witnessed the collision or any events leading up to it, to contact the Roads Policing Unit on 101 or via Crimestoppers on 0800 555 111 and quote RC1610 4385."
Chris Boardman said his mother was "the most positive, outgoing person you could ever hope to meet".
The 47-year-old, who won a gold medal at the 1992 Barcelona Games, tweeted a photograph alongside a tribute to his mother, who he said "never lost her love of the bike or competing".
He also wrote about her "generosity of spirit" and love of the outdoors, recalling fond childhood memories of walking and exploring as a family in north Wales.
"We love you Carol, may the wind be ever at your back," he said.

The Spanish-language TV network had cancelled its contract to broadcast the Miss USA pageant which is co-owned by Mr Trump.
Univision had said last week it would not air the pageant because of what it called insulting remarks about Mexican immigrants.
Mr Trump is running for the 2016 Republican presidential nomination.
Mr Trump has accused Univision of stifling his freedom of speech in order to boost the Democratic Party frontrunner, Hilary Clinton.
While announcing his candidacy earlier this month, he had accused Mexico of sending rapists and other criminals to the United States.
He also pledged to build a "great wall" on the US border with Mexico and insisted it would be paid for by Mexicans.
He later insisted he was criticising US lawmakers, not Mexican people.
US TV network NBC has also said it would not be airing the Miss USA and the Miss Universe pageants both owned by Mr Trump.
Responding to the announcement, Mr Trump said he would consider suing NBC.

Their 367-run partnership in a 425-1 total - the second highest in List A games - saw the Lions beat Sri Lanka A.
Duckett's 131-ball 220 not out was the ninth-highest List A score ever, while Bell-Drummond hit 171 off 139.
"Those guys are very capable of playing international cricket," said Flower, who now coaches the Lions.
It was a successful tri-series for Flower's team, as the Lions beat Pakistan A and Sri Lanka A twice apiece, with batsmen scoring more than 150 in each fixture.
Duckett scored 163 not out in a seven-wicket victory against Pakistan A on 19 July, before excelling again in Monday's 140-run win.
Dawid Malan - the 28-year-old Middlesex batsman who received his first England call-up for the Twenty20 squad against Sri Lanka in June - struck 185 in an 88-run Duckworth-Lewis win against Sri Lanka on 21 July.
Full international Sam Billings, who has played five ODIs and seven T20s, hit 175 in Sunday's second victory against Pakistan.
"I think English cricket will be better for these guys having to force their way in," Flower, who led the national team from 2009 to 2014, told the Tuffers and Vaughan Cricket Show on BBC Radio 5 live.
"These youngsters have to push their way in and earn their spot. It was an incredible series of innings and great partnerships, the selectors will almost certainly take interest in these results."
And the 48-year-old had special praise for Northants' 21-year-old opener Duckett, who he described as "a very talented young man".
"None of us can foresee the future but there's no reason why he can't go on and have a very successful international future," he said.
North Wales Police has renewed an appeal for witnesses following a road accident in which Olympic cyclist Chris Boardman's mother died.
[NEXT_CONCEPT]
The US presidential candidate Donald Trump has filed a multi-million dollar lawsuit against Univision.
[NEXT_CONCEPT]
England Lions batsmen Ben Duckett and Daniel Bell-Drummond could play for England within a year, according to former national coach Andy Flower.