Consumer Reports is advising people not to buy a popular, low-weight bike helmet because of a potential safety risk.

The Pro-Tec City Lite helmet failed a routine bike helmet safety test. The chin straps and buckle that should keep the helmet securely on your head in the event of an accident failed to function properly in three out of the four helmets tested.

In one case, the buckle broke; in two others, a strap broke loose from the body of the helmet simulating what might happen during an accident.

“This type of failure can be a problem, because the helmet can come off your head or it could move out of position during an accident. If the helmet is not in the right place, it’s no longer going to offer the right protection,” said John Galeotafiore, Consumer Reports product tester.

Pro-Tec plans to recall the City Lite helmet and says it will work with federal regulators on an appropriate remedy.

But in the meantime, since the helmet is still available for sale for a short time, Consumer Reports is urging consumer not to buy it.