If you are using an analog USB handbrake, you must calibrate it to ensure the game recognizes its full range of motion. Switch to the tab. Select Calibrate Axles .
Keep this at 100% initially. If you find you have to pull the lever too far to get a full lockup, lower this value slightly (e.g., to 85%). Advanced In-Game Vehicle Setup Adjustments automobilista 2 handbrake