Ha...both my brakes and my sons make a royal racket despite mine being new last summer.
No bells needed as you say, just some braking and every one knows you're behind them...
I can actually play a tune on mine (I'm not kidding), front brake is a noticeably lower frequency than the rear brake so I break alternatively (v-brakes), left is bass drum, right is snare and I can crank out funky drummer and we will rock you...
Unfortunately my son's brakes re just a feckin' racket, sound completely detuned so he can't crank out lines like I can...shame...sure there are some tunes we could've done with 4 notes available.