Originally Posted by
hagen2456
Wouldn't that often be with a more solid helmet than for...
...where the helmets mostly used seem to be of very little benefit - given the speed, what we know of helmets, and the statistics of fatalities in the TdF, Gd'I etc.?
No, typically not: they are made to the same standards (in the US). There is one difference: MTB helmets often have a visor. (There is a difference for downhill MTB riding, but there are other differences there too).