What is the difference between radius and rocker?
The radius is the center of the blade which you glide on, and the rocker is the toe and heel of the blade.

What does the flex number mean on the shaft/stick?
The number on the shaft/stick reflects the pounds it takes to flex the shaft/stick to the optimal point of performance.

Can you do a light sharpening on my skates?
No you can't do a light sharpening on your skates per say. Although you can do a shallower hollow which would in turn feel like a light sharpening.

What is the difference between a freeskate sharpening and a combination sharpening?
The difference is the depth of hollow. A freeskate is a deeper hollow than a combination.

How long does a t-blade runner last?
It generally lasts approximately 3 - 5 times longer than a conventional sharpening.