Progressive Fork Springs For Harley Sportster Forty-Eight Progressive's 'original' progressive rate fork springs, designed soak up the small road bumps and improve front end stability and comfort. Features: Progressive rate fork springs soak up the small road bumps, yet are firm enough to absorb the molar-rattling ones Spring rates have been chosen to reduce front end dive during braking, yet still provide excellent ride comfort Progressive Rate Fork Springs have several advantages over straight rate springs, advantage of a rising rate resistance to compression this helps in varying road conditions from small road imperfections to pothole filled roads The benefit of this is that the spring can be soft enough at the start of the travel to offer a plush ride, yet be firm enough at the end of the travel to soak up the big bumps Ideal performance improvement when installing chrome lower forks They eliminate sag, reduce nose dive under braking, improve stability and increase ride comfort Lifetime fork springs warranty Sold in sets that include correct spacers for the application