YSS Rear Shock Spring 64/66 260mm YZ250F FX YZ450F FX WR450F

YSS High Performance Shock Spring.

Getting the spring rate right will make a huge difference to the handling of your bike, and will often help reduce the effect of bumps.

YZ250F (14-18) YZ250FX (16-21)

YZ250F (19-21) Second Spring Chart

YZ450F (10-13) 

YZ450F (14-21) Second Spring Chart

YZF450FX (16-21) Second Spring Chart

WR450F (16-21