have blades on one of my bikes and I changed the springs to the stiffer ones
There are 3 rates for OG Blades, 12Nm (yellow) is like Classics turned all the way up, 16Nm (red) is like Sprints turned all the way up, and 20Nm is for people who want to colour match a blue bike 🙂 I think there is also an 8Nm (silver) spring for Blade2, which is like a Keo Easy
Mine go back a few years at a time when there were only two options available. I've just looked, and they have '12' on the underside. I have Keos on two of the other bikes.
There are 3 rates for OG Blades, 12Nm (yellow) is like Classics turned all the way up, 16Nm (red) is like Sprints turned all the way up, and 20Nm is for people who want to colour match a blue bike 🙂 I think there is also an 8Nm (silver) spring for Blade2, which is like a Keo Easy