i just backed my Caster down to 7. Ill let you all know what I notice when I get done playing softball tonight.

 

You don't have nine degrees of caster. Caster cannot be measured with an angle finder. Angle finders can only be used to make sure caster is equal on both sides and that's it. Because of steering axis inclination, caster has to be measuerd in an arc and angle finders only measure straight angles. If SAI was at zero, then an angle finder could be used, but it is not. You need an alignment machine or a manual caster gauge at the very least.

 

If you truly had 9 degrees of caster your drive shaft would be vibrating like a mofo.

 

why can't you? As long as you use the balljoints as a reference.

 

If you cant measure caster with an angle finder, I think someone should edit that in the DIY thread that talks about adjusting caster.

If you lengthen the Control Arm to raise the angle finder by one degree, are you not actually adding one degree of caster?

 

No, you are not.

 

I think it should be noted that what Rob is referring to is a more accurate way to measure caster vs. the way most of us do it - and in that regard, what he was saying was correct.

The way Rob is referring to is like in this video: ehow.com/video_2327627_tips-adjusting-caster-measurement.html

Isn't that right Rob?

 

Yes. Either a manual caster gauge, as in the video or an alignment machine. Again though, I reiterate, you cannot measure caster whatsoever with an angle finder. IF we were measuring the tilt of the ball joints, with absolutely nothing else involved, then yes, we could use an angle finder. However, because of SAI, all an angle finder is good for is making sure both sides are equal and nothing more. As viewed from the front, the definition of SAI (steering axis inclination) is the inward tilt at the top of the steering axis, as compared to verticle. Since we have this built in angle, this changes everything as far as angle finders go, because now we have to measure caster as an arc, created by the end of the axle or spindle. Angle finders cannot read an arc, so the only way to measure caster at all is with a manual caster gauge or an alignment machine. IF the steering axis was verticle as viewed from the front, only then could an angle finder be used to measure caster. So, because of SAI, does caster move one degree when we adjust the control arm for one degree on an angle finder? No, it does not.

 

If you cant measure caster because it is an arc that makes sense, however, if you connect the two ends of an arc, would that not lead to an agle? Would you be able to measure an angle somewhere on the rig, or is that what the 100000 dollar alighnement machines do?

 

No. You cannot. By doing that, you are removing the arc and taking the measurement in only one place. I never said an alignment machine was the only way. Just that it was one way. I also mentioned a manual caster gauge, such as this.

htt p://5xracing.com/i-127089-fastrax-camber-caster-gauge.html

These have been around for close to a hundred years. Nothin new.