lesund Twilight: Norways Man Made Coastal Masterpiece HD Wallpaper Bishop BMF Soft Spring Kit. Everybody is different, and Bishop understands that, if you're a lighter skier or just love that knee to the ski turn, they've developed a softer and more responsive spring to customize Bishop BMF telemark bindings to your turn. These springs work with both the BMF R and BMF 3 bindings. Four springs are included, enough for one pair of bindings. These springs are 30% softer than our standard spring. They will give you a lighter feel, quicker lead changes, and allow you to flex your bindings a bit further. Check out this nerdy graph: