Progressive Heavy Duty Fork Springs For Harley Big Twin The heavy duty version of Progressive's 'original' progressive rate fork springs, this suspension upgrade will soak up the small road bumps and improve front end stability, as well as increase comfort for heavier riders or bikes that tend to carry heavier loads. Features: Recommended for riders over 225lbs 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, including a rising-rate resistance to compression, which helps in varying road conditions from small road imperfections to pothole-filled roads The benefit of this is progressive spring rate 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 spring warranty Sold in sets that include correct spacers for the application