caster camber scrub ackerman rake trail

[nutz4sand]

Originally Posted by bdkw1

The closer you can get the lower ball joint to the center of the tire and the less KPI you can run to get the proper scrub the better off you will be.

I am gonna put some thought into this (but likely tommorrow when I gets up!) but any explaining you can do as to why this is would be really great. Thanx Bill

[LiveWire]

Originally Posted by LEE1969GB

How does King pin inclination affect the handling, I assume the wheel will lean more on full lock? I noticed when I first saw protodies buggy it seems to have a lot of KPI shell we call it (takes me forever to type)

Yes, it will lean more.

Originally Posted by bdkw1

The closer you can get the lower ball joint to the center of the tire and the less KPI you can run to get the proper scrub the better off you will be.

QFT

Originally Posted by nutz4sand

I am gonna put some thought into this (but likely tommorrow when I gets up!) but any explaining you can do as to why this is would be really great. Thanx Bill

See red above.

Originally Posted by LEE1969GB

...
scrub radius.
where a line through the top and bottom ball joints meets the ground within the tyre width, Do you aim for about the center of the tyre? stops the wheel being ripped out of your hands when you hit a big bump with one wheel.

You want some, just not too much. I think I have seen 1" suggested as a nice amount. In my own experiences have not been able to get down that low so it has just been the less the better.

Originally Posted by LEE1969GB

ackerman,
This is set up by drawind a line through the center of the rear axle through a line between the top and bottom ball joints at the point where the track rod is to go, This makes the inside wheel turn more than the outside wheel.
Rake,/ trail
Not sure, I know on a motorbike its to do with the difference between the holes for the forks and the steering stem in the yokes but not sure how it works on a car.

You are describing a rule of thumb to attain Ackermann. If you want to verify the means you used gave you the intended results, lines drawn at right angles to both front wheels (while turned) should intersect each other at the same point as a line drawn through the center of both rear wheels. If you have idler arms in your steering or your rack is forward or back of the outer tie rod ends, the rule of thumb will be off.

[DrakAttack]

Originally Posted by Bugpac

Ill get after it... what are you 12hrs time diff? so its like 1 am monday there now?

[LEE1969GB]

Originally Posted by LiveWire

You want some, just not too much. I think I have seen 1" suggested as a nice amount. In my own experiences have not been able to get down that low so it has just been the less the better.

Please excuse my ignorance but 1" from where? I would assume the center of the tyre or the inside edge of the tyre where it meets the ground.

[LiveWire]

Originally Posted by LEE1969GB

Please excuse my ignorance but 1" from where? I would assume the center of the tyre or the inside edge of the tyre where it meets the ground.

0 scrub would be the center of the tire. 1" would mean the imaginary line through the ball joints would hit the ground 1" inside of the center of the tire.

[LEE1969GB]

I think it needs more camber at full bump, any opinions?
The pics are full droop, ride hight and full bump, it is just a rough mock up to see where the pivot points etc need to be.

[nutnbolt2002]

Do you need more camber for sand than hard pack? I thought camber is used to over come the tire wall flex and to keep a much of the tread face on the ground. Soft side walls more camber hard side wall less.

[LEE1969GB]

Sorry Pics,

[plkracer]

Yeah, you need more. That is probabbly 3 degrees or so at full bump. You want 8-10. Keep it at 0-1 degrees in at full droop. Move your upper/inner pivots down, then adjust static camber using your heim.

[nutnbolt2002]

0 at full droop and 3 at full bump is no different than for hard pack. 8-10 are you meaning here caster?