Wilder had -- at least partially -- blamed his extravagant pre-fight wardrobe for his last loss to Fury in Feb. 2020 ... saying the weight of his battery-powered laser attire affected his legs.

But, Wilder ain't quitting on the costume idea just because of that ... so say designers Cosmo and Donato, who tell us The Bronze Bomber already has a new, extravagant look ready to go for the fight this weekend.

C&D -- who created the 2020 piece and others for Wilder -- say they've designed a cool, yet "significantly lighter," outfit for the Oct. 9 tilt ... and promise there will be no issues whatsoever surrounding this one.

"It's going to be significantly lighter," Cosmo said, "So, we don't have any drama at all."

C&D tell us Deontay has already tried on the costume -- modeling it in their store two weeks ago -- and the fighter has made sure it'll have no effect on his ability to punch Fury on Saturday night.

"He looks so amazing," Cosmo tells us. "He was so happy ... The outfit fits perfectly and he's ready to slay!"

C&D wouldn't reveal the whole costume to us ... but they did say it took 3 weeks to make, and features a special red and black theme.

"It's red and black from the Nigerian tribe," Cosmo says. "The red means funeral -- it's going to be Tyson Fury's funeral the next fight."