I managed to get myself stuck behind a couple of lorries tarring and gritting a country road on the way back home today. As well as tyres stuck up with tar and grit I had plenty of chippings pinging off the underside of my downtube leaving chipped paint. It's nothing that a few minutes with some enamel paint didn't put right but I did wonder about getting a strip of helicopter tape to put along the underside of the downtube.
Helicopter tape seems to have become very popular and I've got a small amount on the bike already, however it does seem to attract dirt and dust around the edges of the application and I assume that it's only really going to protect the paint against chipping; since it's a flexible film I don't expect it'll do anything to prevent something that would put a ding into,or damage, the metal. The occassional paint chip can be quickly repared with a spot of paint. Since it's not particularly cheap I was wondering whether people felt it was a worthwhile investment. Also, should I apply it to the whole length of the downtube, it seems to be the lower half that's most prone to strikes?