He approached Wellington Street and an SUV nudged out at the busy intersection, leaving the 40-year-old in instant peril. “That car is coming towards me," he thought.

"I looked down and saw the bumper touching my leg ... (I'm thinking) I really need to get out of here, otherwise I'm never going to make it. I looked down and then looked ahead hoping to get away, but I didn’t."

Then, in Bill's words "it was all over". The car smashed into him. It wasn’t at high speed, but that didn’t matter.

People gathered around, telling him not to move. Bill doesn't remember whether he was in pain but screamed anyway.

"That was the moment I looked down at my leg," the married father of two says. "I couldn’t see my foot … I’ll never get rid of the image from my mind.

"I saw two white bits sticking out from below my knee and flesh. It was very bad. My leg was hanging off and bent back the other way.”

By Bill's own admission he's made "somewhat of a miraculous recovery" from the crash that almost claimed his life. So it’s hard to think that here, 13 months on, he’s talking about getting back on two wheels.

As it happened, a paramedic and doctor - who were both off-duty - were just metres away when the collision occurred.

The paramedic, a Bondi local, was on his way to work when he stopped at a chicken shop for an early dinner. The doctor, a vascular surgeon in training, used the belt from his shorts as a tourniquet. An ambulance transporting another patient up the road serendipitously arrived soon after.

“Whilst it was tragic, it was very fortunate that the planets aligned,” says NSW Ambulance chief inspector Brian Parsell who arrived shortly after, describing it as "one of the more significant lower limb traumas" he had witnessed in his 30-plus years of being a paramedic.

“A classic combination of events occurred. He was inexplicably lucky.”

Bill was admitted to hospital as an amputee - "the nurses would come in and be surprised I still had a foot" - and would spend eight weeks there.

The first operation "to clean the road out" was followed by other procedures that attached two titanium rods into his leg and grafted skin from his back, spanning shoulder to waist.

As for recovering back at his Darlinghurst home, the task of getting up and down the stairs just using his upper body was a brutal one. He suffered flashbacks and feelings of guilt.

"It was a great relief to me that there was dashcam footage and to find out that I hadn’t done anything wrong,” he says. “There’s still a part of me that wonders if I could have done anything different."

The driver was initially found guilty of negligent driving occasioning grievous bodily harm and disqualified from driving for 18 months. This was later quashed on appeal.

Bill's still shattered that his motorcycle was written off - the only thing salvaged was the number plate. "The bike became a massive part of my life and gave me the ability to let go and forget about everything," he says.

"I want to get back on a motorbike. The thought of not riding again terrifies me. It feels like part of my life would be ripped away."

But for now, a bicycle is giving him added purpose. After participating in a three-day ride from Sydney to Wollongong and back again two years ago, Bill was planning another ride last year before his injury.

Not to be deterred, he's been training for the Tour de Cure's signature ride from Sydney on May 3, which will finish in Geelong eight days later and raise money to fight cancer.

He calls it "an extraordinary and somewhat ridiculous challenge". The trip, over 1400 kilometres and taking in more than 16,000 metres of elevation, will test Bill’s “somewhat bionic and still broken leg”.

He's more than halfway through his fundraising goal and hopes to "utilise my disaster to put that money to do something good, to give back". Five years ago, his father had prostate cancer, while his wife’s grandfather and uncle died of cancer.

It could even be harder than when he was lying on Bondi Road, he says. "It won't however be harder than having cancer and that is why I'm riding,” Bill adds.

His short-term goals aside, he’s worried about the possibility of post-traumatic stress disorder striking later on. For now, he's "not getting taken down a rabbit hole".

"It may not be the real world but it’s working," Bill says.

"I thought I was going to die. The whole thing was an amazing circuit breaker for my life. As a result, I feel more calm than I have in years."

To donate and track Bill's progress, visit his Tour de Cure page