Traditional Geometry Truck Question.

[TheKraken]

I was in the skate shop near my house the other day and i confused myself very badly.

When you look at a Randal Style truck you can tell it'll be carvy or stable because you can estimate what angle the hangar is at just by looking. But how can you look at a Bennet style truck and tell whether or not it is carvy?

[Rich Nelson]

i'm with you, its hard to tell because although with standard trucks their pivot cup is generally at a pretty high angle the kingpin is not at a 90 degree angle to the pivot so the truck cannot turn as smoothly

[TheRosen]

try drawing a line in your head from the axle to the pivot. its not nearly as exact but you can get a feel for it.

EDIT: not positive, but i think that part of the reason that a bushing is traditionally round is so that truck designs can have the bushing seat so offset and still use the same bushings as a perpendicular kingpin. i also think the reason they're designed the way they are is for strength and clearance reasons (both between the board and the truck AND the truck and the ground). this is all my speculation though.

[msk]

EDIT: not positive, but i think that part of the reason that a bushing is traditionally round is so that truck designs can have the bushing seat so offset and still use the same bushings as a perpendicular kingpin. i also think the reason they're designed the way they are is for strength and clearance reasons (both between the board and the truck AND the truck and the ground). this is all my speculation though.

Standard trucks are the way they are because they're based on rollerskate trucks, which existed for several decades before anything specifically made for skateboards. Tracker and Bennett basically modified existing designs, optimizing them for skateboards. Strength and clearance aren't inherent to the design, those (along with width) were the modifications that Tracker and Bennett made. Rollerskates didn't need strong trucks, and ground to kingpin clearance wasn't an issue (many rollerskate trucks had the kingpin only a few mm off the ground).

Perpendicular kingpin trucks didn't come until later, so they are using the same bushings as standard trucks, not the other way around...

[Archy]

Just a thought, but don't the turnier non-reverse kingpin trucks (Bennetts, Tracker rtx) often have a little kink in the hanger at the pivot to change the angle? I agree it makes it harder to eyeball how it might feel.

[enemy combatant]

try drawing a line in your head from the axle to the pivot. its not nearly as exact but you can get a feel for it.

It's actually a line from the center of the pivot cup to the point where the hanger bushing face intersects the centerline of the kingpin. Truck with steep pivot pins like Indies or Bennetts try to rotate around the pivot pin but they end up with the whole hanger just leaning over (and binding a bit) along the above mentioned pivot axis.

[SteveC]

It's actually a line from the center of the pivot cup to the point where the hanger bushing face intersects the centerline of the kingpin. Truck with steep pivot pins like Indies or Bennetts try to rotate around the pivot pin but they end up with the whole hanger just leaning over (and binding a bit) along the above mentioned pivot axis.

Indeed.


Like this.

thanks to pvd

[TheKraken]

ooooooohhhhh. I see now. Very interesting stuff. Thanks for the help guys