Suspension Upgrades for Harley Big Twin Motorcycles. The Big Twin Suspension collection at TC Bros is built for riders who demand superior handling, comfort, and style for their Harley-Davidson Big Twin motorcycles. This category features premium shocks, springs, and suspension components designed to enhance performance and ride quality. Perfect for models like Softails, Dynas, and Touring bikes, these parts are crafted with precision engineering and durable materials to handle the toughest roads and sharpest turns. Whether you're upgrading your factory suspension or customizing your ride, TC Bros suspension solutions deliver the reliability and performance you need to ride with confidence.