Truck Design

[chaindog]

I have a question about the efect of kingpin angle on truck turning.
Am I right in suspecting that lower kingpin angles in relation to the base plate will make for a turnier ride?

[Longboardloser]

No, higher kingpin angle = more turn.
Example: Randal 180 (a carving truck) 50degree angle
Randal DH (stable downhill truck, less turn) 35degree angle.

[Michael Billings]

You can even get a 60 degree randal baseplate, it is meant for luges.

[chaindog]

are you sure youre not thinking of pivot angle?

[Captain Hampton]

Randals are different from indy's, trackers, etc. The ball-pivot angle and axle form a "T" shape, so what you see is what you get for a turning angle.

As for conventional trucks, I've got no frikken clue man. Here's two pictures Peter Verdone and Chaput showing conventional vs. Randal/Gullwing geometry respectively:

[Longboardloser]

Kingpin angle, pivot angle are the same thing, "hanger angle" is hard to define on "traditional" style trucks, so it's not.

[chaindog]

Go to this site for details suporting my side http://www.chrischaput.com/randal/ read the whole thing

[Michael Billings]

Do you mean the whole 5 degree positive castor or whatever? It just means that the axle is put 5 degrees forward, meaning more carving...
This is how I understand it.

[chaindog]

no i mean at the bottom about randall using pivot angle not kingpin angle to decribe their trucks and about the luge trucks with a 60 degree pivot angle are the turniest of them all.

[WesE]

On any truck, the pivot axis is an imaginary line from the part of the pivot closest to the deck, to the surface of the inner bushing that touches the hanger. The two pictures show that. The relationship of the pivot axis to the flat surface of the baseplate that touches the deck/riser is the pivot angle.

Kingpin angle is unrelated to the pivot axis and obviously not the same thing as the pivot angle.

[Super Veg]

Do you mean the whole 5 degree positive castor or whatever? It just means that the axle is put 5 degrees forward, meaning more carving...
This is how I understand it.

look at Chris Chaput's website for more info about positive and negative castor

[chaindog]

Scratch castor scratch everything in this topic except the effect Kingpin angle has on turning. WesE if you had read my post you would realize that i already linked to Chaput.

[longboardertwan]

kingpin angle should have no effect on turning. Think it through. Imagine a traditional truck, then keep the hanger the same and change the angle of the kingpin. If you keep where the hanger touches the bushing in the same place but change the angle at which the kingpin goes through the angle of pivot is still the same.

[chaindog]

Im sorry i wasnt clear i meant on a randall type truck, through the hanger kingpin.

[Captain Hampton]

I have a question about the efect of kingpin angle on truck turning.
Am I right in suspecting that lower kingpin angles in relation to the base plate will make for a turnier ride?

Yes. For the randal type truck, a hypothetical angle of 0/180 degrees would make for a turny ride (except that it's impossible to get any leverage over the trucks at that angle). A full 90 degree angle, perpendicular to the baseplate, would result in lean only. There's a custom board maker Svartled who made a board producing a 90 degree angle for the rear truck.

In a torsion truck (excate, baku, original supercarve) or seismic truck, the effect is reversed; a 90 degree angle would result in the turniest angle but with zero leverage (or you're fuct in other words).

Simple mechanics.

[chaindog]

Thanks, Im designing a super low super light truck that will be capable of changing from turny to stable quickly

[silversurfer]

Thanks, Im designing a super low super light truck that will be capable of changing from turny to stable quickly

I would love to see that.

Have you seen herbn's trucks?

Or Svarteld's?

They are working on similar concepts.

I can find the links if you are interested.

[chaindog]

Sure give me some links. I,m at school right now

[silversurfer]

Sure give me some links. I,m at school right now

Check out all 9 pages of herbn's stuff, especially all the light and
low trucks he makes.

http://www.longboard_skating.homeste...ns_stuff5.html

Let me know what you think.

[Nickle]

If I understand the question correctly, the kingpin should make a 90 deg. angle with the pivot axis. This would be the best way to maximize the effects of your bushings. The reason these don't
is because of the location of the axle with respect to the kingpin. I.E. the kingpin would have to pass through the axle.

Another thing to consider is that if the kingpin passes between the axle and the pivot cup, it will have higher loads on it then if it would pass behind the axle. In other words, harder bushings would be needed to achieve the same turning ability when the kingpin passes before the axle. This is assuming that both trucks have the same geometry.