front suspension problem

[juvius]

i posted this question (sort of) in another thread i started in the "Photo Gallery & Project Log" but i thought it may be better as it's own thread.

I've been playing around trying to get the front in right for days now, I just don't know what to do.

i bought new front shocks but they sat way too high, so i put the best two original shocks on (set to the stiffest setting) and it seems to set too low. as you can see in the pics, the right front tires is getting severely worn.

also, the toe moves so much and i can't figure it out. i've set it with weight in it and without weight.

am i just expecting too much out of it?

here are the pics:
http://s629.photobucket.com/albums/uu19/dawnehale/gokart3/

i also put a few pics of my CVT. do they looked lined up ok?

 

[Doc Sprocket]

For the record- I am not a suspension engineer. That out of the way, it is my personal opinion that a single arm suspension (others, too) are best set up so that with the kart at static loaded weight, the arms are parallel to the ground. This means combined weight of the kart, gasoline, oil, battery, and you. If your camber is not acceptable at this point, re-do your knuckles. The reasoning behind having the arms parallel to the road is it will be at the most neutral position between compression and rebound, and allow you to dial out as much bumpsteer as you possibly can. Without some serious re-engineering, you won't be able to dial it ALL out, but this will minimize it. So- with the arms parallel to the ground (put a bunch of weight in the kart to simulate you), then adjust your tie rods to achieve your steering centre and desired toe setting. If your caster or camber are adjustable, now's the time.

It's worth mentioning that all this alignment and setup stuff is much akin to peeing directly upwind if you've got a bunch of worn bushings, balljoints, or rod ends. The slop will cause mayhem with the alignment while you're moving.

Another thing I always feel the need to point out- All too often, I see people setting their suspension up so that even with the kart fully loaded, there is zero available down travel at the wheel. WRONG! ALWAYS set it up so that with the vehicle at ride height (again, loaded), the arms have some down travel available. Otherwise, your kart is half-suspended- about as useful as a half-vasectomy.

 

[theo]

A 2 seat is not a good buggy for single a ams, because of the weight range an a limited amount of travel.
So you have to go with stiff shocks and set up the droop so you don't go past 1 or 2 deg.

Looking at you front suspension, you have terrible bump steer, because of where your bell crank is positioned. You also have no Ackerman and no caster.

Can you show some better pics of the front end.

 

[juvius]

I'll get some more pics tomorrow. It got too dark on me. Ive been out plating around with it. Its a lot closer to being ok but not quite there

 

[bighead]

bad worn shocks make these yerfdogs drive bad.

 

[juvius]

bad worn shocks make these yerfdogs drive bad.

the old shocks that i replaced were actually already replacements in pretty good shape. i think i have located the problem... my right a arm in curved back towards the frame about 1/2 inch to 3/4 more than the right. i put the new shocks back on and with my weight in it, the camber looked pretty good, but once i took off down the road the front end raised way up and caused some very extreme outward camber... so seeing that happen, i put the best two older shocks, adjusted them stiffer and put them on. same as the first but worked out much better.. now when i sit in it there is almost 0 camber but once i take off, the front end raised and gives me slight outward camber... now i have to get the toe set right... i think the longer tie rod is bowing under pressure and the tie rod ends are kind of loose.

so, i think once i get the right a arm, longer tie rod, all of the tie rod ends, and the right spindle replaced, i'll be ok... i think maybe some newer stock type shocks may help as well, but i'll look at that once everything else it taken care of.