Using a ski helmet for winter biking I am curious if anyone uses a skiing helmet for winter biking? Would this be safe? Are skiing helmets designed to protect you from the same kind of accidents that you would have on a bike?  

My thinking is that a ski helmet would:


Help to keep your ears warm
Would fit well with ski goggles (which fit poorly with my bike helmet)
Not have air vents in it which make you cold in the winter
I wear a Bern Brentwood with a winter liner in cold weather. It's a certified bike helmet, but designed more like a ski helmet. The winter liner does a great job of keeping my ears warm without wearing any other protection, but doesn't block traffic noise. It is vented, but not well enough that it makes my head cold. It also has a clip in the back for ski goggles if you're using them. With the summer liner it works well for fall and spring, too.