Up to 1,000 people dressed in Harris Tweed jackets set off from Clerkenwell to take part in the annual London Tweed Run.
The event, which took in the major landmarks, is described as a "bicycle ride with a bit of style".
Cyclists stopped for tea in Tavistock Square and lunch in Kensington Gardens.
Crowds took photos as the well-dressed riders, some on vintage bikes including penny-farthings, toured the capital's streets at a fairly leisurely pace.
The riders, who also finished in Clerkenwell, were warned that "proper attire" was expected but bowler hats were a "spot more aerodynamic than top hats".
"We take to the streets in our well-pressed best, and cycle through the city's iconic landmarks," a spokeswoman said.
"Along the way, we stop for a tea break and a picnic stop, and we usually end with a bit of a jolly knees-up."
Hundreds of cyclists swapped lycra for flat caps, trilbies, berets and their sartorial best during a 12-mile ride.