Turtur overseeing new Tour Down Under era

The new-look last day of the Santos Tour Down Under is only one of many changes at Australia's biggest cycling race.

Mike Turtur. Source: AAP

The Tour Down Under has entered a new era and it's unclear how long race director Mike Turtur will stay in charge.

There have been wholesale changes at Australia's biggest bike race, which starts its 21st edition on Tuesday with a 129km stage from North Adelaide to Port Adelaide.

The most glaring change is the new final day, which will be the Queen Stage at Willunga rather than the Adelaide Street Race.

It means the overall champion should be decided on Sunday afternoon - normally, all the race leader has had to do on the last stage is keep out of trouble.

Last month's sudden death of Paul Sherwen, the veteran TV commentator and long-time friend of the Tour, sadly adds to the feeling that things are different this year.

Less obvious to fans, but massive for the race, has been a big turnover of key staff.

People such as event manager Sally Heading and media manager Gennie Sheer had worked on the Tour for well over a decade.

As traffic logistics manager, Terry Roberts was one of the Tour's most important people in its first 19 years, but he died two years ago after illness.

The change of SA government early last year is another important factor for the Tour, given the race is first and foremost a state tourism promotion.

Turtur agreed that the race has a new feel about it.

"We have had a massive turnover (of key staff). You just have to deal with the circumstances as best you can," he said.

"We are very fortunate, our people who've come in have done really well.

"We've lost a lot of knowledge and a lot experience. Like most things, you get on with it."

Turtur, who created the race and is one of a handful of people to have been to all 21 Tours, will be out of contract in March.

"We've had some discussions, but there's nothing that's been fully agreed," he said of his future.

"I'm certain they (the SA Government) will make an announcement ... if not, I will go fishing."

While much has changed at the Tour, there will be two constants on Tuesday - Turtur's nerves and the searing SA heat.

"I'm feeling like I always do - I'm always nervous and tense," Turtur said.

"When you venture out onto the open roads, no matter how much planning you do, things happen."

The temperature will hit the 40s until a cool change on Thursday brings relief to the race.

The weather has prompted course changes on the first two stages.