Around 30 people set off from Alexandra Park, Alex Way, in Stamshaw, at around 2pm today.
Ian Henden, 72, from Fareham, has been taking part for the last nine years, having previously been the organiser.
The 72-year-old takes part to promote cycle safety, environmentalism and nudity.
He said: 'There's too many people getting knocked off their bikes.
'And there's only so much oil available in the world.
'Up until the 1800s the amount of oil reserve stayed pretty much constant.
'Since then the reserve has decreased exponentially as the demand increased exponentially.
'We're using oil faster than it can be created, it's going to run out and when it runs out we get wars.
'We're not saying don't use oil but we're saying use it sensibly.'
And he likened telling children nudity is wrong is akin to 'Victorian child abuse'.
He said: 'This helps to overcome the Victorian child abuse which is so prevalent in this country where children are being taught by parents that nudity is wrong.
'It's not wrong, up until about 1800s people quite happily walked naked in fields, went swimming in the local swimming pond and went swimming on the beach.
'They did not worry if they were naked.'
The majority of riders were men, with two women taking part.
The ride left Stamshaw at 2pm heading for the seafront.
Lawrence O'Reilly, 58, from County Durham, had come down for the ride.
'I just like cycling naked, there's not great moral reason for me,' he said.
The organised ride had three uniformed police cyclists as an escort.