UBI leaves off Kaisei 4130R. Seems to have roughly equivalent specs to Kaisei 8630R, though I see it rarely. I'm supposing both are heat-treated, but what is the difference? Can anyone vouch for 4130R's liveliness, springiness, stiffness, ride quality???
This is a perfect question for one of the less used parts of this forum. Im sure the guys and gals in the framebuilders section will be much more knowledgable and usefull than the collective here will.