Does mega evolution carry over the effect of previous ability?

Question

I'm exploring to use aggron and considering heavy slam. What I want to know is after I mega evolve an aggron with heavy slam, what will be the megas weight?

Answer 1

Well, if a Pokemon uses Skill Swap on Traunt, does the Pokemon continue to sit out turns?

This is my logic going into this. You lose your ability when you mega evolve, so it's no longer in play and it gets replaced with a new ability (though some Megas keep their abilities, like Tyranitar). While I don't have solid proof, I am very certain that once a Pokemon that has a different ability before mega evolving evolves, the effect of its previous ability will go away.

Hope this helps! :)

Answer 2

Mega evolutions change their size and weight as soon as they mega evolve. So, that would mean your Mega Aggron would go from 797.3 lbs(360 KG) to 870.8 lbs(395 kg). Yikes, that's going to be one powerful heavy slam.

*Side note: An aggron with the ability Heavy Metal's weight is doubled to 1594.6 lbs(720 kg), so almost double the power of Mega Aggrons heavy Slam. However, regular Aggron isn't very good so I would advise you to use Mega Aggron instead

Hope this helped!