“It was incredible, we brought up 20 in the first half hour,” Clement Charret told AFP on Tuesday.
For the past year and half he has been trawling the depths of canals that snake north and east from the capital, “for fun but mostly to clean up”.
With his sidekick Enzo, dubbed “Magneto,” they also found a motorscooter and traffic signs at the portion of the Ourcq canal which cuts through a rapidly gentrifying area outside the ring road that surrounds Paris.
Around 15 of the most recent bikes were recovered by employees of the city's bike rental scheme Velib', while the others were lined up on the banks, draped in mud and weeds, under the shadow of a former mill recently renovated for office space.
Charret, a 20-year-old student who lives in the nearby suburb of Pavillon-sous-Bois, said that while the bike catch was unusual, it wasn't the most interesting item ever plucked by his magnet.
His favourites? “A bayonet from World War I and a revolver pistol from the era of Napoleon III,” he said.
Last year, he managed to snag two World War II shells, a find that prompted the intervention of a mine-removal team.