Organisers of the Australian Human Powered Vehicle Super Series have announced the season's cancellation due to coronavirus impacts and restrictions.
With the first three rounds of the 2020 series already cancelled earlier this year, there were hopes that two modified events - one in Adelaide and one in Murray Bridge - could still be run, but chairman Andrew McLachlan said he was "disappointed" it could not come to fruition.
Mr McLachlan said while South Australia was well-positioned in terms of handling coronavirus, teams from all over the country, including many from Victoria, were involved in the sport and the safety of competitors, teams and the community was "paramount".
"We have worked vigorously to find ways to safely and responsibly hold events in a very difficult time," he said.
"The Board has come to this decision with a heavy heart, but it is the right decision, a responsible decision."
He said the series' events were classed as "very high risk" and required a COVID-19 Management Plan, which had not yet been produced by the state government, resulting in ongoing uncertainty for organisers and teams.
"I lament the disappointment endured across our entire community in not being able to enjoy and benefit from actively participating in our wonderful sport this year,' he said.
"It is, however, timely to remind ourselves of the difficulty and challenges far greater than ours many around the world are suffering right now.
"Our resolve, energies and commitment will now turn to making the 2021 UniSA Australian HPV Super Series very special."
The Murray Bridge 24-hour pedal prix event brings thousands of people - and dollars - to the town and wider Murraylands in September every year.
City of Murray Bridge mayor Brenton Lewis said not having the event would be a loss for the town.
"I met with Andrew a few months ago, and they hoped they could maintain the Murray Bridge event," he said.
"I'm very sorry to see them make the decision; it would've been very hard to make the decision, I know Andrew was holding out as long as he could.
"It's not totally unexpected, but it's still very unfortunate."
He said local businesses needed as much trade as they could get at the moment, and he had hoped they could have capitalised on having the pedal prix event in the town.
"Local businesses supply goods, and the supermarkets do really well," he said.
"It's a traditional event and we look forward to it every year."
Mr Lewis expected the council's financial contribution towards hosting the pedal prix would be "kept in the reserves" to be put towards other community-based initiatives and events.
"We have a $400,000 total events budget every year and we expend it, and we're willing to do so - events bring a lot of people to Murray Bridge," he said.
Geoff Wood, who manages GTrikes, one of the leading HPV teams, said it was a disappointing decision but completely supported it.
GTrikes was founded in 2012 and is based in Ballarat, but has team members in both Victoria and South Australia, and Mr Wood said restrictions and border closures made the prospect of racing this year hard.
"It was becoming more difficult to organise our participation in the events," he said.
"Most of our riders come from Victoria so competing with border restrictions in place would have been almost impossible.
"Up until the situation worsened in Victoria, we were more confident of getting some modified racing in."
He said pedal prix was a "huge part" of some of his team's life, and believed he would lose some members who would move on from the sport.
"We'll now use the rest of the year to prepare for next year; build new vehicles, do some more testing and hopefully hit the ground running," he said.