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Rear Castor
8smokingbarrels - 2/7/03 at 10:05 PM

Does castor angle have much relevance to the rear suspension. i know how important it is to steering, but does it affect the rear in any way. If so what sort of angle should it be at?

BTW what is the best way to measure things like KPI and Castor. I hear lots of figures (5 degrees positive for castor etc) but am wondering how exactly u measure these angles

chris

kb58 - 3/7/03 at 02:58 AM

Re your first question, I've never read anything about it mattering.

Buy a digital level, they're great for measure auto-related alignment stuff.

Alan B - 3/7/03 at 12:37 PM

quote:
Originally posted by kb58
Re your first question, I've never read anything about it mattering......


Yes, me neither.
I understand that castor is primarily (if not entirely) to aid in the car running straight after steering (self centering) so isn't really applicable at the rear.

I'd certainly aim for zero castor for ease of building.

I guess it is possible that castor could come into the equation with anti-dive/anti-squat systems, but I still don't see how....

In fact castor works at the front because the wheel is trailing, whereas at the back traction would want the wheel to lead perhaps.....pull rather than push.....if you see what I mean......

Hmmmm?......

[Edited on 3/7/03 by Alan B]

kb58 - 4/7/03 at 12:55 AM

I was going to mention anti-dive/squat, but that doesn't have anything to do with how the upright is angled fore/aft. The "anti-" stuff all depends on the side-view inclination of the trailing arms. But I suspect Alan already knows that, this was for everyone else...

Alan B - 4/7/03 at 01:17 AM

Yes indeed, I agree...

I meant that castor was something that would exsist, and possibly change in a "anti" system, but could not imagine how it could affect anything.......as you say it's a matter of the inclination of the trailing links..........and their extended point of intersection and it's location...(I think???)...

All confusing enough without me adding to it....

Rorty - 4/7/03 at 04:13 AM

Yup, castor has no effect on the rear.
I have another poser, but rather than hi-jack this thread, I'll start new thread > Caliper Position.