A cyclist from Camberwell, south London, who last week had her bike stolen from a sabotaged bike rack has alerted others to the new method of theft.
The rack Sarah King locked her bike to had been cut through, but the damage was hidden by tape. That meant thieves could remove the tape and slide her bike lock through the gap in seconds.
Her tweet about the incident, which incudes a picture of the slice through the metal, has been shared by thousands of people.
Cyclists please watch out for gaffer tape on bike racks covering up that they're cut straight through pic.twitter.com/RRiJYVfnwV— Sarah King (@sezking78) February 25, 2016
Sarah said cyclists should check any racks with suspicious tape to make sure they are secure.
She added she was "upset and shocked" after she discovered her bike was missing because "I love cycling in London and I love my bike".
Locking a bike to an official rack with a decent lock is the only option for many cyclists, so knowing many could be compromised is a worrying prospect.
Cyclists concerned about theft, especially those with high-value bikes, might want to consider cyclist insurance.
Bikes under a certain value can be included on home insurance policies but cyclist policies may have better options and fewer restrictions for where you can store your bike and include features such as breakdown assistance, personal accident cover and cover for accessories.
Learn more about the best cycling insurance policies here, where you can also find out about using insurer-approved locks.