New GoKart, Needs Steering Adjusted

[babzog]

Picked up a kart for my son this weekend. The spindles have no caster to the them (they're vertical) and the kart actually appears to have the ackerman reversed - the outside wheel appears to turn more tightly than the inside wheel. Control arms are forward of the spindles and point straight ahead. Linkage at steering shaft is via two link points, not one stacked upon the other. Also, the right-hand tie rod is much longer, almost 2x as long as the left. I'll get some pics of it later on.

It's not so bad right now that I have it dialed back to a relatively slow speed for him to get used to, but at higher speeds, it's very twitchy and tends to plow straight ahead (rather than turn) in corners. Wondering how I can fix it to make it more manageable?

 

[Doc Sprocket]

You've answered many of your own questions. What did you need us for?

Search for a thread called "Camber, Caster, Ackermann". Plenty o' good info there.

 

[landuse]

Picked up a kart for my son this weekend. The spindles have no caster to the them (they're vertical) and the kart actually appears to have the ackerman reversed - the outside wheel appears to turn more tightly than the inside wheel. Control arms are forward of the spindles and point straight ahead. Linkage at steering shaft is via two link points, not one stacked upon the other. Also, the right-hand tie rod is much longer, almost 2x as long as the left. I'll get some pics of it later on.

It's not so bad right now that I have it dialed back to a relatively slow speed for him to get used to, but at higher speeds, it's very twitchy and tends to plow straight ahead (rather than turn) in corners. Wondering how I can fix it to make it more manageable?

Seems like you know what the problem is. All you gotta do now is fix it

 

[babzog]

Seems like you know what the problem is. All you gotta do now is fix it

Well, that's what I'm trying to work out.... how to best fix it.

I suppose I could simply cut the spindles off and re-weld with the caster set from 10-12* but how do I go about measuring that (ie: what tool would I need? OR, how do you guys do it?)

As for correcting ackerman... I understand there's a way to set ackerman at the steering column end of things when the tie rods are forward of the axles and the steering arms are pointed forward. Just need the lowdown on that... there was another thread on ackerman that described it (measure the angle between centerline of kart and a line from rear axle center to kingpin, then locate the tie rods along a line drawn at the same angle from steering column out on the bellcrank). If that's the correct way to fix the ackerman while keeping the tie rods ahead of the axle, then I just need to know how far along the bellcrank to locate the holes. OTOH, if there's a better way to fix the ackerman, then please, edumacate me.

 

[landuse]

This is a good thread to read that Toystory mentioned

http://www.diygokarts.com/vb/showthread.php?t=11760&page=3

 

[babzog]

Yeah, that was the thread I mentioned reading.

 

[theo]

Without a pic to look at, I'm guessing at this, but try this. Put the right tie rod in the left hole and the left tie rod in the right hole, other words cross them over (steering shaft bell crank). You will have to extent the tie rods. This will give you ackerman, is it enough, I don't know?

 

[Doc Sprocket]

It is likely not enough, but a start, nonetheless. I DO suggest whipping out the ol' grinder and realigning things. As far as what I use- I have a couple of different angle gauges. One is a simple gravity powered unit that has a pointer and a gradiated scale. The downfall is relative angles. If the surface you are referencing is not level, you need to do the math to determine the relative difference. My new angle finder is a treat. It's got a digital readout, and you can re-zero it at any angle, so figuring out a relative angle is a no-brainer.

 

[babzog]

Finally got the pics off my camera. Youy can see the wonky steering setup. There's another weird thing... when I turn the wheel fully left, the whole frame shifts to the right (pushed by the wheels). The same does not happen when I turn the wheel fully to the right. What would cause this?

 

[Doc Sprocket]

Gadzooks, I hate factory setups like that! If it behaves differently left to right, odds are good that something's off- often, a twist or bend in the frame will cause this. It could be putting more weight on one side than the other.