what is that motorsport called...

[10 Pence Short]

Where they're in the Alps and have to get as far up the hill as possible? Big power and some wacky machines.

Trying to find some youtube footage but can't remember its proper name.

[snowy slopes]

I think you are looking for the rachau hillclimb, which ran from 1995 to 2004. They used all sorts of much modified bikes and skiddoos to tackle this hill, which was sponsored by red bull. HTH