08-20-2006, 01:02 AM
If you want full face protection, then you need it all the time. 30 mph vs 60 mph does not mean that you will hit the pavement (or a fast moving vehicle) with your face any less hard. Oftentimes it is the velocity of the vehicle hitting you which is the deciding factor. I was on a bike ride a couple of years ago and one of the guys who was riding with the group slammed into a runner from behind while going 40 mph downhill. The runner's cheek and chin was totally hamburgered and he required significant plastic surgery to reconstruct his face. His velocity was approximately 10 mph before the crash. Also, several years previously I was hit from behind while standing still on my bike by a car going about 40 mph. I fortunately avoided face/head injuries, but the differential impact velocity was on the order of 40 mph, sufficient to completely destroy my bike and tear tendons and ligaments.