Why Pedro Acosta paused mass damper use during 2025 MotoGP season

Pedro Acosta has explained why he elected not to join the Tech3 riders in continuing to experiment with KTM’s mass damper system during the 2025 MotoGP season.

After the factory's early turmoil, Acosta and his crew settled on two effective base set-ups for the RC16, which he used to claim twelve podiums in the second half of the year on his way to fourth in the world championship.

“I tried at the beginning of the season, and we removed it. I had enough to do [without] even thinking [about] the mass damper,” Acosta said at the penultimate round in Portimao.

“I was quite happy with the bike that I have now. I have two base setups. If I need one thing, we go in one direction. If I need other things, I go in another direction.

“And generally, that's working quite okay for me. I know the bikes that I have. And I work around the problems that I have.

“For these reasons, and because it's only two races to go, it's not really necessary to put [new] things. We will have one day in Valencia to try all these things.”

Acosta, like the other KTM riders, duly tested different 'mass damper' boxes on the back of his machines at Valencia. 

However, after losing the morning to a damp track, he made clear, “the priority for today was the aero.”

Earlier in the season, Tech3’s Maverick Vinales explained the benefits and challenges of perfecting the mass damper.

“It's very important to make it work, because if it works, it's a good improvement, it can take out a lot of vibrations. So basically, you can be faster,” he explained.

The problem was that sometimes “when it's very hot, the configuration is not always the same during the run, so then the chatter increases.”

Vinales also confirmed that just because a rider was using the larger seat unit, it didn’t mean there was something inside.

“I only have the structure, but I don't have the mass damper,” he said at Mugello.

“I would like to use it, because I think it's a step, but at the moment we need a little bit more time. Because in Austin, it was working really well until something happened, and then the vibration was huge and I could not finish the sprint.”

Honda likewise experimented with revised rear seat humps during 2025, widely believed to contain a new version of a mass damper. 

“It’s something we are testing, and we need a bit more time,” Luca Marini said at Portimao, before refusing to confirm or deny the device’s presence: “We cannot talk about it.”