People are being urged to report their stolen bike to the Gardaí.
Figures show almost 3,000 bicycles were stolen across the country during the first eight months of last year.
Over 70% of the bikes reported stolen were in the capital.
However cycling groups believe the figure could be closer to 15,000, with many bike thefts going unreported.
Dublin Cycling Campaign Chairperson Úna Morrison told The Hard Shoulder people need to report their stolen bike.
"We think that for every bike that's stolen and reported to the Guards there's at least three to four that haven't been reported," she said.
"When it's going towards those numbers as we estimated there, 15,000, then it makes something that the Guards might set up and pay attention to a bit more.
"There is a value in reporting and letting the Guards know, and letting people know that there are more cyclists around.
"That's part of our mission in the Irish Cycling Campaign is building that awareness as how people cycle as transport.
"So, anything like that that will add to the numbers will help".
Ms Morrison said to prevent theft in the first place, people should use "the most expensive lock that you can afford" and lock a bike in multiple locations - such as the wheels and the frame.
"Using a couple of different locks will slow people down, parking in more segregated and proper facilities... it's lit, there's people there, there's loads more space.
"More and more employers are bringing that in for their staff," she added.
Ms Morrison said people should also take note of the serial number of their bike in the event that it is recovered.
