Oversize fees apply for checked baggage exceeding 55 lbs. It cannot be checked in it exceeds 99 lbs. If baggage exceeds 62 total inches ( width + length + height) oversize fee applies. It cannot be checked in if it measures more than 79 total inches ( width+ length + height).
For more details visit : http://www.volaris airlines.com/Baggage/Baggage-Information