The annual Martin Jennings Memorial Run has been postponed because of weather concerns, organisers announced on Friday morning.
In a statement shared on Facebook, they confirmed the event, which was due to take place on Sunday September 13, has been deferred until the following weekend. Rain is forecast for the morning, with conditions expected to improve later in the day.
Organiser David Saunby said: "Due to rain in the morning and drying up later in the day, because of safety reasons, the Jennings Run is postponed for one week."
He added: "The safety of those taking part in the Jennings Run is paramount when organising a run of this size.
"It would have been unwise of me to ignore the weather information given to me on my phone this morning when speaking to Jeff Jacobs of Weather Cornwall, whom I have trusted over the last five years and who has always got it right."
Mr Saunby said there were also "other factors involved in organising the Jennings Run".
"To ride in wet conditions with a large number of bikes could be a recipe for disaster, especially for less experienced riders having to cope with spray and poor visibility," he said.
"I also have to consider that if I had decided to ignore the forecast and an accident happened due to the wet weather, I would be the one who would have to shoulder the blame for going ahead when advised not to.
"Furthermore, we would not get the numbers and the charity would suffer."
He is encouraging those planning to take part, as well as the thousands of spectators who line the pavements each year to watch the bikes pass through towns and villages across Cornwall, to remain patient.
He reassured supporters that "the Jennings Run will happen if it takes until Christmas."
Martin Jennings Memorial Run Postponed a Week Due to Weather