The black trucks pivot didn't have the flash finish. Therefore I decided to make my own pivot cups, custom fit to this hanger and baseplate combo.NOTE:It's not advised to ride random hangers and baseplates together as their is the chance the hanger can pop out of the baseplate when sliding or cornering harshly. NOTE: This may not be suitable for use in hot climates due to the low melting point of Polymorph .Polymorph is fun and useful material to keep around so it might be worth buying a decent amount. As you can see on the gif above, and as you already know, this is the decrease in pressure inside the cup that makes the cup stick, because the pressure outside is much bigger. The thrust aspect is much more obvious in TKP trucks due to their design geometry that more evenly splits the responsibility to carry the load between the bushings and the Pivot. It's important to maintain the pivot cups to keep your ride smooth and responsive, whilst keeping the movement of the board reliable and predictable. (example.
Their effect and contribution to the overall feel and control cannot be overstated so let’s take a look at what they do and why they are important. I would need more time to compare the cups on different surfaces, with different loads, and for long periods, but I am satisfied and I think it is a success.

The pivot cups are a crucial part of the longboard truck, and are often over looked or forgotten about. Over the years we have found that most stock pivots that come with a set of trucks do not perform as well as homemade and aftermarket Pivots. Therefore if you want to remove a suction cup, don't pull it away from the wall because it will make the pressure inside much lower, and the suction cup will stick better. First of all do these stick to skin? They allow a truck to turn smoothly, whilst holding alot of the riders weight. Some truck companies are trying new techniques when it comes to pivot removal and installation. this is awesome! the red truck did and looks alot better. It is characterized by both rotation and angulation at the pivot point. Put 2 teaspoons of the granuals in a mug and pour the hot water in the mug. There are exceptions in the precision truck category, but for the most part stock pivot cups for skateboard and longboard trucks should be replaced if you are interested in having the smoothest and most stable ride possible. In few days I'll publish a new instructable in which I use these suction cups, and another one concerning a technic for 3D printing.