What started in Sydney as an event to breakdown the negative stereotypes surrounding motorbike culture, The Distinguished Gentleman's Ride has grown across 648 cities in 101 countries.

In addition to funding prostate cancer research, the charity has now partnered with The Movember Foundation in support of raising money for men's mental health

Host rider in Chile, Santiago Lombardi said the event there drew around 1,200 motorcyclists in support of the "silent illness that is the third cause of death in the country."

Founded in 2012 by Mark Hawwa, the idea was sparked by an iconic image of Mad Men's Don Draper looking debonair on a vintage Matchless motorcycle.

The 2018 event mostly held on the final Sunday in September has raised nearly $US6 million ($A8.4 million).

One of five key organisers based in Sydney, Stephen Broholm said the day gives men who have been suffering alone for years a chance to talk about their health concerns.

He sees the passionate support and momentum each annual ride receives bolstered by the fact that many men find it difficult to ask for help.

"The Distinguished men's ride has been a great conversation starter, it's helped men develop friendships and encourage each-other to seek support," Mr Broholm told AAP.

"Men are just really bad at taking care of themselves."

Australian Associated Press