The riders, whose ranks included quite a few elegant ladies and a brave chap in a kilt, converged on the Grease Monkey for a cruise from Braddon to Kingston via Mount Stromlo to raise funds for the Prostate Cancer Foundation.

"It's not about the fastest bike but the classest act," Canberra event organiser, Simon Whittaker, who stood out in a dashing denim suit snapped up on Ebay for just $200, said.

"Participants have raised more than $33,000 in the last four weeks and a total of about $60,000 over the past three years."

The Distinguished Gentleman's Ride, which began in Australia, is an international phenomenon. This weekend more than 40,000 people were expected to take part in rides in 400 cities in almost 60 countries.

More than $1.7 million was raised for prostate cancer research in 2014.

While many riders readily admitted to being of an age and gender likely to benefit from a better understanding of prostate cancer, Fairfax was told the main reason for taking part was that it was a fun day out and a great way to enjoy your bike with like-minded riders.

While the wheels ranged from well-used examples of popular Japanese brands to the latest stars from Britain, America and Italy, it was the older classics that turned heads.

Most of these, including a highly desirable Brough Superior belonging to Peter Davey, were owned by members of the Veteran, Vintage and Classic Motorcycle Club of the ACT.

Mr Davey's bike, an example of the marque favoured by Lawrence of Arabia, is an SS80 from 1939.

"The 80 means the manufacturer guaranteed your bike would reach 80 miles per hour [130km/h]," Mr Davey said. "This one has a side valve, 1000cc V-twin. It was not the company's fastest bike. That would be the SS100, which had an overhead valve engine, and was guaranteed to be good for 100 miles per hour [160km/h]."

While Mr Davey's SS80 is a worthy asset, with a street value of about $80,000, the SS100 is for serious collectors only. A disassembled one is currently for sale overseas with an asking price of almost $400,000.

Mr Davey's bike is one of the last of about 3000 Brough Superiors ever built.

"When the war broke out the factory retooled to make the camshafts for the Merlin V12s used in the Spitfire [and a range of other planes]," he said. "They did not resume operations [as a motorbike manufacturer] after the war."

The Brough Superior was not the oldest bike to take part in Sunday's ride. That honour may go to a beautifully unrestored AJS that appeared to date from the early 1920s.

And, for anyone doubting if this was truly an event for distinguished gentleman, the question is beyond dispute.

ACT government minister Mick Gentleman added the finishing touch, completing the event on his 1974 Yamaha DT 175.