I'll admit a mistake I made and will give some advice. If you've upgraded the speed gear, using it against Impact Man is a terrible idea. His hitbox is large enough while he's charging and you'll land if you try to jump over him while he's slowed down.
A younger me would've called foul at this, but to be honest, I do think it a bit clever. The game punishing an over reliance on the speed gear as a crutch.
Oh yeah, for an example of how powerful the power gear can be. Here's me doing a challenge.