Barnett has cryo'd aluminum clutch drive plates that will fit our bikes. I have used them in every street bike I have owned for along time. I just ordered a set for the vfr. The part number is 402-35-078069c. They also had an older part number they wanted that was HP-69-20. They don't show them on their website. You have to call them to order. Half the weight and it is rotational too which means the engine should rev a little faster. I have these in my ZRX1100 with around 120 at the back wheel as well as the XZ550 Visi0n that I road raced and I have never had any issue with them. Neat upgrade.
That I'm not sure of as I didn't even check the price of stock ones. I would imagine they are more since they cryo and hard anodize the aluminum. You have to pay to play.