RG> I've heard that putting a cover on a helmet can be 
 RG> a bad thing. If the helmet contacts the ground the 
 RG> cover will prevent the helmet from sliding on the 
 RG> pavement and can instead snag causing neck 
 RG> injuries. 
 
That's correct.  The outer shell of a bike helmet is designed to be slick so 
that it doesn't snag on the pavement.
--- Maximus 2.02
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