After the recent hail storm here in Melbourne at Christmas, I had a local rider contact me asking for a bike assessment. He said his road bike was on the roof rack on the car as he was driving home when the storm front hit. There was significant damage to his car, so he wanted to be sure his bike was still safe to ride.
He did a visual inspection and couldn't see any damage but thought he would bring it in to us to provide a professional assessment. I examined the bike first visually and also could not see any obvious damage, however when I did the Ultrasound scan a number of delamination indications became very obvious on the scan. All up there were 8 delaminations spread out across the top tube. The damage was akin to small hammer hits, which is pretty much what golf ball sized hail is, the top tube was the only tube on the frame damaged which makes sense as it was fully exposed to the hail.
It was recommended that the frame was unsuitable for use in this condition. Once again this shows the value of Ultrasound scans to find non visible damage and determine the safety of your bike.