Take the flex out of your EX500 and solid mount the engine. They make a BIG difference in stiffening up your race or street bike. All mounts are made to be as light as they can be, yet retain their strength. Add the shoulder bolts for the down tube and it really stiffens up the frame allowing the suspension to do its job. These two mods are probably the best bang for the buck you can get for your EX500 race bike.