R/C Tech Forums - View Single Post - 1/12 forum
Thread: 1/12 forum
View Single Post
Old 12-10-2015, 09:56 AM
  #43864  
Drew Manzella
Tech Master
iTrader: (35)
 
Drew Manzella's Avatar
 
Join Date: Nov 2007
Location: Christiansburg VA
Posts: 1,068
Trader Rating: 35 (100%+)
Default

Originally Posted by DesertRat
Someone tell me if I have any part of this wrong, as it’s literally all I know about reactive caster:

Caster is the angle of the kingpin, always angling back to the rear of the car, with a typical range from 0-10 degrees. Increasing your caster will typically result in less turn-in but a little more control, more steering exiting the corner, and somewhat increased straight-line stability with less tendency to wander because a wheel running caster will tend to straighten itself. Less caster will usually give you more off-power steering, but often with correspondingly less on-power when accelerating out of the corner.

Running reactive caster attempts to use both of these aspects to increase overall steering: when the car loads up on the outside front tire, the caster angle decreases, increasing the front end ‘hook’ as you enter the corner and then giving you the high caster on-power steering as you exit and weight is transferred off the front end. More reactive caster means more overall steering, but can mean you may have to adjust your driving style to drive more ‘ahead of the car’, needing to predict where the front end will grip.

As grip increases, less reactive caster is the normal tuning change made to keep the front end of the car from gripping too hard and oversteering and prevent traction roll. Static caster adjustments are still used to change the cars on power / off power steering balance.

Is this actually true?
It sounds mostly right to me - though there is such a thing as positive and negative caster (even though I can't think of a front end that will give negative if assembled correctly). Positive is the kingpin leaned backward and negative is the kingpin leaned forward.

Caster affects steering through the resulting camber gain as the car is steered. Reactive front ends pull camber out (via reducing caster) as a result of suspension travel.
Drew Manzella is offline