Polaris

[Functional Artist]

When I worked for GM I was taught rear steer spindles the tie rods were under compression and prone to flex. Front steer spindles the steering was less prone to flex. The reason being the tie rods were always under extension. You see, the wheels are always trying to splay outward from the front when moving forward. Which is why I feel tubular tierods would help make your situation better. Just my 21/2 cents worth.

Hey Denny,
That reasoning makes sense
...& again, thanks for continuing the discussion (helping me & hopefully others understand this stuff better)
...but, do cars have their front wheels toed inwards or are they running "true"?

Here's where my thinkin' is (after thinkin' it thru a few more times)

If the front wheels are "toed in" a little bit (like they are on this & many karts)
...& the kart is going straight forward
...it seems as if rear tie rods would actually be, being "pulled on" or in tension
But, when the kart turns all of that "goes out the window"
...& on turns, the tie rod on one side would be in tension
...while the other side is in compression

The Domino Effect

So, it seems like a (my) component choice (big, plastic wheels) + a design error (short spindle arms) added up to create an effect (an overleveraged steering shaft)

Then, when them big, plastic wheels flexed (on turns)
...& then, flexed back (into shape)
...they sent that energy, thru the tie rods, to the steering shaft (causing it to flex)

Then, when I added the center brace (stiffening the shaft)
...it just resulted in sending that feedback, up to the steering wheel

* The wheels are 20" across
...so, from the axle to the edge of the wheel, would be a ~10" "lever"
...& the spindle arms are ~3 1/2"

So, the wheels currently have a "leverage" advantage of ~3:1 over the spindle arms

 

[Denny]

All automobile wheels are toe’d in around 1/16”. More on early automobiles. The RULE is rear steer in compression. Front steer in tension.
The thing is all the automotive rules also apply to our gokarts! Caster, camber and toe, all the same rules and measurements. We keep to the same numbers because they are universal. So why wouldn’t the dynamics of the material!

 

[Functional Artist]

All automobile wheels are toe’d in around 1/16”. More on early automobiles. The RULE is rear steer in compression. Front steer in tension.
The thing is all the automotive rules also apply to our gokarts! Caster, camber and toe, all the same rules and measurements. We keep to the same numbers because they are universal. So why wouldn’t the dynamics of the material!

Hey Denny,
After your response, I thought it thru again

I imagined what would happen "if" the tie rods were totally taken out of the equation
...which would eliminate toe in &/or out &/or if the kart has forward or rear steering

So then, it seems like whichever way a vehicle is moving, the front of the wheels should/would "splay" outwards
...because when a wheel is mounted outside of the spindle, the rolling resistance, of the wheel, kinda drags the wheel backwards a little
...causing the front of the wheel to "splay" outwards

So, "if" a vehicle is moving forward, without any tie rods, the front of the wheels should/would "splay" outwards
...& consequently, "if" a vehicle, without any tie rods, was moving backwards, the rear of the wheels would then, "splay" outwards

So, now (I think) I understand (if the above makes sense)
...& agree with you pal (thanks for your persistence)

 

[Denny]

Now you got it! I wanted to explain the principle not just give an answer or possible solution with out knowing why. My guess it is why Manco went front steer on most karts. To keep from bending tie rods!
Give a man a fish and he eats for a day.
Teach a man to fish and he can drink beer all weekend!

 

[ezcome-ezgo]

What you need is a tie rod made out of magic. At the end of the day, the drunk fisherman can't stand up, can't clean his fish and can't eat. But he isn't hungry, his belly is full of beer. So he meets this college drop-out, a young woman, who decides she likes his boat. She can't clean a fish either so they go to Checker's (AKA Rally's) and get some overpriced, over-seasoned sandwiches and sit and watch the sunset. The fisherman sobers up and begins to feel this overwhelming sense of the impending doom of commitment. He gets up, jumps in his boat and get's the heck out of there. The girl becomes the CEO of Bass Pro Shops and still can't clean a fish.

 

[Master Hack]

Mag Lev! all those steering problems go away!

 

[Functional Artist]

What you need is a tie rod made out of magic.

...or a steering damper (AKA steering shock)

IMO this situation is similar to them big 'ol 4 x 4 trucks
...where they install oversized tires
...& then, need ta add a damper to the steering system
...because them big 'ol tires "send" every little bump in the road, back up the steering shaft, to the steering wheel

 

[Master Hack]

So is rhe problem 3 Fold? Wobbley wheels, flexy rods and shakey steering?
those big 4x4 trucks usually have a rag joint in the steering column to solve the latter.

Amazon.com

thats my usless fact of the day.

 

[Functional Artist]

So is rhe problem 3 Fold? Wobbley wheels, flexy rods and shakey steering?
those big 4x4 trucks usually have a rag joint in the steering column to solve the latter.

Amazon.com

thats my usless fact of the day.

Hey T,
IMO them plastic wheels flexing (wobbling) is the "root cause"
...which made the steering shaft flex
&
Then, when I added the center support, it stopped the steering shaft from flexing
...but, the wobbly wheel effect was then sent up to the steering wheel (making it shake)

So, a steering damper (like used on 4 x 4 trucks) should/would absorb or help control the "feedback' from the wobbly wheels
...but, them wheels would/could still be a flexing (& there's no fixin' that)

* I'ma thinkin' that if run on a track with mostly gradual turns, these wheels probably wouldn't wobble much at all
...it's just the hard/tight turns that they don't like too much

So, I don't think it's a terminal issue
...I just wanted ta know why it was a doin' what it wasa doin'
...but, I'll keep an eye on 'em for sure

 

[Master Hack]

Just thinkin out loud… what would be involved in switching to a wire spoke wheel?

 

[Denny]

I’d get rid of the rubber tie rods first!

 

[ezcome-ezgo]

What's the diameter of your wheels now?

 

[Functional Artist]

What's the diameter of your wheels now?

The wheels are ~20" across (or tall)

So, it looks like, from the axle to the edge of the wheel, would be a ~10" "lever"
&
The spindle arms are ~3 1/2"
&
So, I would believe that means, the wheels have a ~3:1 "leverage" advantage, over the spindle arms

 

[ezcome-ezgo]

20" Wheels

20 inch wheels are now on sale, low rider wheels with twisted spokes are now on sale,

www.mrbikeshop.com

 

[Functional Artist]

20" Wheels

20 inch wheels are now on sale, low rider wheels with twisted spokes are now on sale,

www.mrbikeshop.com

Hey EZ,
Interesting
IMO probably more "for looks" than added strength
...& WOW! are they expensive

I still don't think this is a terminal issue
...it's just something to keep an eye on (like "knowing" one of your karts limitations)

It's easily drivable (like this)
...it doesn't seem like something is about to fail or like it's dangerous to drive

The shaking doesn't even seem to effect the control too much
...especially if you know NOT to turn sharply & don't get 'er to shakin'

So, I'ma gonna run 'er this way for a few more tests