Caster Angle

[baxter650]

Is there be any benefit to running more caster angle with larger tires?

[BC40]

The guys on BC4x4 indicate the oposite is true with big tires.

The point of tire contact (perpendicular to the hub) and the geometry of where the caster line meets the ground ahead of it increases as the radius of the tire increases. So as the center height of the hub increases less caster is needed to have the same effect/force on the tire. Or so I have read.

[Tapage]

Originally Posted by BC40

The guys on BC4x4 indicate the oposite is true with big tires.

The point of tire contact (perpendicular to the hub) and the geometry of where the caster line meets the ground ahead of it increases as the radius of the tire increases. So as the center height of the hub increases less caster is needed to have the same effect/force on the tire. Or so I have read.

Interesting theory .. I always thought and believe that it's totaly viceversa .. more huge tires ( distance from the surface to the hub ) more caster it's needed ..

[redline fj55]

Originally Posted by baxter650

Is there be any benefit to running more caster angle with larger tires?

ohh hell yah there is an advantage with more caster. we usually set it at -5 to 6.
plus it helps a lot when you crest over a steep and sharp spine.
(on xrra buggies, colorado hill climb race cars, fj55, 40.)
havent tested it on other setups yet .
cruiser axles have +1 degree caster. thats the landcruiser loose steering highway feel.

[Medusa]

-5

[fj40charles]

Originally Posted by redline fj55

ohh hell yah there is an advantage with more caster. we usually set it at -5 to 6.
plus it helps a lot when you crest over a steep and sharp spine.
(on xrra buggies, colorado hill climb race cars, fj55, 40.)
havent tested it on other setups yet .
cruiser axles have +1 degree caster. thats the landcruiser loose steering highway feel.

Are you talking about negative caster????? Positive caster is what you want.

[redline fj55]

Originally Posted by fj40charles

Are you talking about negative caster????? Positive caster is what you want.

no. negative caster is what you want.
and if you dont want to believe me thats fine, then i will be passing your slow ass on the trail! nyuk nyuk nyuk....

[Medusa]

I have never seen an off-road car with purposely-designed negative caster, so when you pass my slow ass, would you be kind enough to stop so I can observe it

[redline fj55]

Originally Posted by Medusa

I have never seen an off-road car with purposely-designed negative caster, so when you pass my slow ass, would you be kind enough to stop so I can observe it

shot myself in the foot on that one.
I thought for sure neg caster was leaning back not foward.
so yes i agree with ya.

[hammerhead]

Yes, large tires at stock caster will usually death wobble where 5° positive castor drives sweet with 38.5s

[baxter650]

That is what i thought but i want to be positive before i cut and reweld.
Thanks alot guys, Vince

[hellbent40]

is it true that you can offset the caster.... like 4 degrees drivers side and 5 degrees passenger side .. to help with high steer and turning angles...

thats what i read... and thats what i turned my too.... total 14 degrees for drivers side and 15 for passenger side... 10 degrees for pinion angle... will see how it works

and i agree positive castor