How long do trucks usually last grinding on that axle? Been skating for most of my life and spoiled myself in my adult years of buying too many new trucks due to the madness, so I've only axled one set of 44's that I still got. Little bit peeking through on one of em, the other truck probably soon. I just retired em thinking they'd probably break next slappy but maybe I'm wrong?
It all depends on what you are skating and how hard you are grinding, especially on rough or nasty edges.
Some trucks will never get through to axle with the amount of wax and slippery edges or nice coping, but others can burn through a set very quickly if skating super rough or unfinished edges, pool coping, crusty curbs, or anything where the truck metal (axle included) is softer than the material they are grinding.
There is one curb that I know people skate and we don't know what was in the mix when it was poured, but it will eat trucks faster than anything else, no matter what is put on it, as well as it being almost still completely intact while other curbs are very worn down.