Bones Street Tech Formula powers the legendary Bones STF wheels that roll fast, grip when you need to and slide when you want to, without flat spotting. STF gives you more control to skate with confidence. Bones STF wheels outperform all other wheels, and because they wear so well, they last several times longer than normal wheels, making STF wheels the best for less. Bones STF wheels are available in the original 103A and the new 99A Easy Streets™ for greater roll, control and softer landings on rougher terrain.

Shore Durometer A Scale is good, but it does not cover the entire range of skate wheel hardness and is very limited because the scale goes from 1 to 100 and anything over A 95A does not compute accurately.

Shore Durometer B Scale is perfect for skate wheels because:

1. It is very similar to the A Scale, but reads 20 points lower, allowing the useful scale to be extended by 20 points, which covers the entire hardness range of skate wheels in one scale. It uses the same soft spring as the A Gauge, but the conical gauge needle of the D Scale.
2. Because the spring is soft, the B Scale gauge needle does not puncture the skin of the wheel surface, resulting in the same reliable reading as the A Scale does.

Shore Durometer D Scale is designed for hard rubbers and rock hard urethanes, not soft, bouncy urethanes that are used in skate wheels. It has a very stiff spring behind its sharp conical needle and often punctures the skin of the wheel being measured, this resulting in 5-10 points softer reading than is correct. Thus, Shore D Scale should not be used for wheels in the useful skate wheel range.