Australian F1 Grand Prix boss Ron Walker is re-evaluating his life after a brush with death but has no plans to step down as chairman of the big race.

Mr Walker underwent emergency brain surgery on Monday after hitting his head on the road when he fell off his bike while riding around the Tan in Melbourne’s Royal Botanic Gardens last month.

Mr Walker, 70, knew he had broken a couple of ribs in the fall but was unaware of brain damage until last Saturday night when he was unable to button up his shirt or tie a Windsor knot as he was getting dressed to go out.

A visit to a neurosurgeon on Sunday and an MRI scan showed he had a clot on his brain which required immediate surgery.

Surgeons at St Vincent’s Hospital drilled a hole in the front of his forehead to relieve the pressure, which could have caused a seizure.

“You do reevaluate your life and think about how much more leisure time you can fit into it,” Mr Walker said.

He said while riding in the park he ran into some debris and went sailing over the handlebars, hitting his head on the ground.

He was wearing a helmet.

“I banged my head and didn’t think much of it but on Saturday night I asked my limbs to do something and they didn’t obey me,” he told reporters.

“I didn’t know what was going on – I thought it may have been the onset of MS.

“I tried to do my buttons up but my fingers wouldn’t work and I forgot how to do a Windsor knot.”

But the setback and the re-evaluation is not enough for him to consider quitting the F1 chairmanship after Melbourne’s 15th year of hosting the race, being held at Albert Park this weekend.

“I still feel physically fit,” he said.

“I’ve got 45 young people who run the race, I just take credit for it.”

But Mr Walker says he has retired from riding bikes and will settle for walking around the Tan to keep fit.

- AAP