Australian charity cyclist Bob Montgomery has died at age 82, one day after completing a 5,200km bike ride from Broome to Bowral. This was reported by Qazaqyia.kz citing The Guardian.

His family confirmed his death on social media, saying he had died unexpectedly just a day after completing the cycling feat alongside his grandson, Tom, as a fundraiser for motor neurone disease.

In the post, his family said it was Montgomery's sixth interstate fundraising ride in support of Motor Neurone Disease (MND) NSW, "raising vital funds and awareness for a cause that was deeply personal to him".

"Fittingly, and now poignantly, the ride was named One Last Ride," it continued. "At 82 years of age, Bob was still passionately sharing his message only hours before his passing."

According to the MND NSW website, his epic ride raised $104,965 in donations.

MND NSW shared a tribute, saying it was "deeply saddened" by the sudden passing, calling Montgomery a "cherished friend and tireless supporter of MND NSW".

"For many years, Bob dedicated himself to raising vital funds and awareness for people living with motor neurone disease," the group's CEO, Liam O'Meara, said in a statement.

"His most recent achievement, riding from Broome to Bowral at the age of 82 alongside his 18-year-old grandson, was nothing short of inspirational.

"Bob understood that behind every diagnosis is a person and a family navigating one of life's most challenging journeys.

"His fundraising helped ensure that more people could access the care, equipment and support they need, when they need it most."