Building the beast

[Slamwoef]

Hi Amped.

thanx for the link

If i understand what bump steer is and please correct me if i'm wrong is when the suspension moves the steering toe angle changes as the suspension travels?

if my understanding is correct then i did design the steering to compensate. ( built the steering to run in the center line of the chassis and the center of the stub axle)

i checked at full lock on the steering i have no visible toe in or out movement through the movement of the suspension. im not saying its not there but rather by chance i got it very close to rite.

I must admit i didn't know what to call the phenomenon so didn't really research it much, built it on a idea

i will close up the ends of the tubing with plastic tube covers. don't see the need to weld them shut.

 

[Slamwoef]

One thing you might consider is mounting the strut bottoms to the upper control arms - Ball-joints are much stronger than tie-rod joints, the top arms are much stronger than the lower arms, PLUS then the load on the front end will be pushing that top ball joint "together", instead of trying to pull the lower tie-rod joint "apart".

It might make more height in the front end, but you'd be much less likely to have a joint failure. Then again, you might find that mounting them all the way out at the end of the upper arm (less leverage) might offset laying them over some more (more leverage).

i did think about this as well but i don't think i need to worry about it to much, i'm sure that if a tie rod end can hold up to all the steering and braking forces experienced in a 1.5 ton car they should easily stand up to the challenge of supporting a 150kg go kart. Worst comes to worst i think my welds or the tubing will bend before the rod ends give way.

 

[Kaptain Krunch]

i did think about this as well but i don't think i need to worry about it to much, i'm sure that if a tie rod end can hold up to all the steering and braking forces experienced in a 1.5 ton car they should easily stand up to the challenge of supporting a 150kg go kart. Worst comes to worst i think my welds or the tubing will bend before the rod ends give way.

I would definitely think about that for a minute. I completely agree you should mount the shock to the upper control arm. Tie rod ends are not meant to take the type of force you would be exerting on them. Did you weld the ball joint to your steering knuckle? And are those sway bar links i see? I would revise that suspension design a little if you are planning on 40+hp in the future.

 

[OzFab]

My biggest concern is the change in camber through the suspension travel. The advantage of using double arm suspension over single arm is to eliminate camber angle change; your setup has quite a dramatic change

 

[jamyers]

My biggest concern is the change in camber through the suspension travel. The advantage of using double arm suspension over single arm is to eliminate camber angle change; your setup has quite a dramatic change

Good point, especially with a kart that won't have much is any body roll in a corner because of the "solid" rear suspension. Now, if the rear had double A arms and you thought you were going to get body roll, then you might want to build some in.

I'd still rethink having the struts push downward on tierod ends. Granted they're stout for what they're built for, but that's ALL side-loads, nothing in the vertical.