Do not despair.[] The downward travel adjustment, also known as droop, is used to help raise or lower the center of gravity (CG) slightly. On electric on-road carpet cars, it's usually about 4.5mm. On nitro cars, usually 5 to 6 mm. It's also used to keep the bottom of your car from scraping excessively on the carpet or pavement. The lower you can go, the more bite your tires will have.