The phrase "change gears" usually refers to adjusting the speed or direction of movement in a vehicle. However, when it comes to antonyms for this phrase, we can consider context-specific words. In the world of literature or writing, the antonyms could be maintaining a consistent tone or staying on a particular subject. In the world of work or business, antonyms could be sticking to a plan, maintaining the status quo, or refusing to adapt. In the realm of psychology or personal development, antonyms could include stagnation, refusal to grow, and inflexibility. Ultimately, the antonyms for "change gears" depend on the context or industry being referred to.