A recently-retired Mildura speedway champion has undergone surgery for spinal injuries following a crash during unofficial practice for this weekend's Finke Desert Race in Central Australia.

Event spokesman Anthony Yoffa says Leigh Adams crashed his bike on Tuesday afternoon, about 110 kilometres south of Alice Springs on the Old South Road.

Mr Yoffa says it is believed the 40-year-old was riding with his brother and some other Victorian competitors when he ran off the road.

"It is always difficult in these times where there has been a serious accident," he said.

"Our thoughts are with all the riders.

"We ask people to take it easy but if people are out riding their bikes there is little we can do.

"Accidents do happen - that is an unfortunate trait of motorsport."

Mr Adams was flown to Royal Adelaide Hospital where he remains in a serious condition.

Former AFL superstar Tony Lockett will compete in this year's Finke race.

Lockett was not able to take part last year after breaking his wrist in a pre-race crash.

He will compete in the bikes event starting on Sunday.