How/when/why did bells become the accepted method for expressing approval and/or motivating the athletes?
I don’t know when, but cowbells make a louder sound than mittens.
I think people are just answering Christopher Walken’s demands for “MORE COWBELL!” 
Cowbells have been a staple at downhill races for as long as I can remember.
yabob
5
FWIW, there’s several claims out there like the following:
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