purchased for a xr400, needed some stiffer springs for the bike and was changing the clutch out anyways. first off let me say that i love moose products and that this is the first disappointing item i have had from them (rest of their clutch components were great). anyway went from slippage in 5th with stock springs to slipping in 3rd with the moose springs....well ran some test at work and they were about 35% less stiff then the stockers. so sadly i have to say stay away from these and go for barnett or some other company. big let down from moose.