Wheel speed sensor

[mtread]

If you mean the lugs on the (ceramic) rotor, these break very easily. Better off buying new, as the replacement is plastic and doesn't break (unless you try really hard). Make sure you pack it with plenty of grease. I didn't and it made a hell of a noise  :eek
https://www.yamahamotorcyclespares.co.uk...NSOR&uid=0