Can't say how much a bowling ball weighs but they did some testing... "To ensure safety, Shiffer tested it by using a crash testing rig. "We dropped 10 pounds of weight from three feet and it withstood the impact," she said."

The article later goes on to say "U.S. federal safety standards require a bike helmet to protect the wearer's head from an impact that's equivalent to a 6-1/2 foot drop."