Can someone here speak on the differences between 8.5 to 8.25 axle trucks? I’m on 5.8s and am considering 5.6s because I want something slightly more maneuverable and easier to get off the ground.
It is down to your preference.
Between three people, all on the same size boards, there are exactly the two options, as you have mentioned.
I ride the 8.5" truck, because it is more stable and that is what I prefer on all my setups, mainly skating transition or small tech, but not really any rail / stair stuff. That and the more narrow truck just feels too tippy for me nowdays, even though I used to skate that and smaller trucks a while back.
One of the guys always says my boards feel too rigid and he always rides the 8.25" truck, because it gives him the right amount of tip to pop to size / weight, etc.
The other guy often rides both, but when skating more street stuff, he also goes down to a smaller truck to make things more manageable overall.
That is without going into any other info with different truck versions, hollow / forged vs cast / solid or anything else, but even that can change things considerably too, in which ever width truck, along with how many washers on the inside, how worn down the truck is and other factors.
A normal set of standards / team / polished 5.8s are always going to feel a little more solid, chunky, heavy or whatever compared to the same truck in 5.6, but whether or not you will like it more or less is up to you.