A-arm lengths and mounting points help

[Duden89]

If only i would've known all this when I built my offroad go cart last year. Does that say 6 degrees between the centerline of the tire and the kingpin inclination?

[nutz4sand]

Yes THAT one says 6 degrees BUT it varies with the width of the tire and the offset width of the rim so there is no ONE magic number!! Each different combo will be different.

ALSO only seat time will tell you what YOU like but different drivers like a little more or a little less. As mentioned in my post before this one.

[Duden89]

Alright thanks for the help I greatly appreciate it. This will save me countless hours of fixing screw ups

[atomicjoe23]

6* is a very common number, but if you look through a lot of the trophy trucks and Class 1's you will see that 12-14* is just as common (I know it isn't exactly kingpin inclination. . .but most desert racers/fabricators that I have been around and talked to refer to that angle as KPI regardless of whether they're using king pins or other).

My suggestion would be to stay somewhere between 6-12* of KPI as rough upper and lower boundaries.

[nutz4sand]

The width of the tire and rim (offset) will determine where it should be. Till you know that your shooting at stars. Or living on luck!

[Durangokid]

AWESOME!!
So glad I found this forum and thread. this is saving me alot of headaches since I am just doing a buggy as a project to keep me busy, and for fun.

[UkraineTrain]

Are there any books that cater to off road suspension/chassis design? I have Herb Adams's Chassis Engineering and it's good but I feel it's somewhat lacking for off roaders. One thing to consider is A-arm geometry when the arms droop down at static ride height... it's far from the ideal horizontal lower A-arm position but a lot of people do it for ground clearance.

[atomicjoe23]

Unfortunately there are no books that deal with suspension design specifically related to off-road use. . .we have to adapt what we learn from the road-going books and learn what works and doesn't from our own personal experiences and the experience of others.

I've asked the same question before as have many other before both of us and the answer is always the same.

I wish there was a book like that. . .but no one has written it. . .yet. . .

[evan]

IMO after reading a Carrol Smith book cover to cover, you will think Herb Adams is a clown who couldn't design a functional stick. I very seriously suggest reading the Smith books. You will have to re-read many things to fully understand them. The by-product is a through understanding of chassis dynamics and the cause / effect of design ideas. Designing a complete suspension system is a series of compromises. Learn what is traded, mix with input from mbn, and use your judgement.

[ProtoDie]

Camber change I use is approx 3-4 degrees thru full suspension cycle

Pos. 1 1/2 to 2 degrees at droop to neg. 1 1/2 degrees at full comp .

I hope I got the pos. & neg. right,,,I always like to mix those 2 up.

At compression, the top of the tire tilted in.