GY670s on rear. The fronts rivered badly and I changed to the Michelin steer tires.
The ride is much improved and it took only once ounce to balance one tie and none on the other, on a Road Force Balancer.
however the Michelins when wet turned brown. They have orange oil in the compound to suit the environmental crowd.
When is I see brown that says the rubber is deteroriating, on the surface.
The Michelin's life is 5 years. The GY670 is ten. However I've been told repeatedly on either or any they won't re install a five year old tire, on another vehicle.
If any of this is in error someone correct it. Thsi is my understanding.