Not that I do a lot of IM branded races, but for Whistler in 2016, I used a koala shaped squeazy "bell" mounted on the aerobars.
It emitted a high pitched squealing when I used it, which was about 20 X during the event.
Initially, I used it when I was passing a person who was riding erratically.
Then, after I made it to the pointy end of the field, I did it to entertain the kids who were watching in Whistler and Pemberton.
And then, I used it to amuse and motivate myself, as I slogged up the Pemberton Climb, no longer on the pointy end of the field.
Yes, it was worth the aero penalty.
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