250-500cc 09 WR300 rear brakes

The rear brake on this bike doesn't have a lot of power and then it will lock up.The pedal and caliper work fine and no spongy feel. I would like to try different pads and maybe a different rotor if the pads alone don't solve the problem.Has anyone tried a different pad and rotor set?

What's on it solid or wave? What are your pads, sintered, mixed?

It has the solid rotor and Brembo pads.Came stock on my bike.

The stock pads sucked on my bike, try new pads when the stockers wear out.

I had the same problem on my WR250 2009mdl
the problem turned out the be that the eliptical freeplay adjuster needed adjustment (back it off the pedal) and give the pedal more freeplay. without enough freeplay, my rear rotor got so hot, it turned blue and cooked the brake fluid

Mine need constant adjustment. The solid rotors just eat the pads!
My rear pads are dead and my fronts are still at 60%

They work good though if you keep them adjusted.