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Old 10-10-2019, 08:18 PM
zbillz zbillz is offline
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Default Wheel offset question

Hi,
My son has an offset kart we have been working on together.
I noticed the right front slick was low on air. While filling up the tire I noticed that the spindle arm that connects to the tie rod on the right side is really close to the tire compared to the left. It actually scraped the inside of the tire when the air was low.

It almost looks as if the spindles arms were welded a little different between left and right sides?
Is this normal for an offset kart?

I'm worried about the spindle arm actually tearing into the tire under hard cornering.

I took the wheel off and flipped it around with the valve stem on the inside and there is a lot more clearance between the arm and the tire now.

Is it OK to run the tire and wheel this way while the other side is installed the "normal" way?

Thanks!
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Old 10-11-2019, 04:18 AM
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itsid itsid is offline
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usually there are spacers to properly set the front trackwidth and alignment.
there are many different sizes for different tracks and different needs;
and sometimes you need to have one wheel a hair closer to the frame than the other indeed.

So yeah.. could be 'normal'
just measure the distance between the upper rim collar and the kingpin head.
that distance should be identical for identical spacers.

I never came into close contact with an offset chassis myself
(just going round in circles isn't too popular around here)
So IDK what an offset kart needs to leftturn even better really.
but actually I'd assume more stickout right than left;

but chances are the linkages are indeed also optimized for left turns *shrugs*
and indeed of slightly different attacking angle.
But once you measured the rim to kingpin distance you can rule out the spacer being the culprit.
(Orr you can grap a protractor and measure the spindleshaft to linkage angle directly.)

'sid

PS forgive me, but that front reminds me of a Margay kart..
and to my knowledge Margay never made offset karts..
you sure? care to post a pic of the entire kart?
or wait.. was there a coyote with such front end too? *headscratch*
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Old 10-11-2019, 06:38 AM
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By wheel offset, do you mean the hub face offset like car wheels?

On go karts that's typically achieved with spacers (washers) on the spindle. Car wheels are offset so the axis of rotation of the knuckle intersects the ground in the middle of the contact patch (approximately anyways). Go karts can't really achieve this since the wheels are so small, so backspace and offset is kind of a moot point.

You could have something bent, you could be missing a spacer, or the kart could be set up with asymmetrical Ackerman to give it a specific handling characteristic.
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Old 10-11-2019, 10:19 AM
zbillz zbillz is offline
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I don't see any spacers anywhere. When the wheel is off, just the hub.
The 2 spindles are definitely welded different or possibly bent?
Turning the right wheel around (valve stem on inside) takes care of the clearance issue because of the wheel back spacing....may have used the wrong terminology before.
Can the wheel be ran like that?
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Old 10-11-2019, 08:17 PM
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itsid itsid is offline
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Sooo.. that is NOT an offset kart (aka oval kart)!
it's a straight one.(thankfully so!)

I see you're running hubbed front wheels, so the spacer would be behind the hub, not the rim of course. (in- and outside of the hub.. and I think I see some tbh)

And no, the valve should be facing outboard.
(running inboard valves is possible but really bad practise)

if you're willing to remove the seat you can check the spindle linkages..

On that second picture it appears that the left front wheel isn't straight, but in fact runs a bit toe out, so fix that first.
Then again the pitman arm doesn't seem to be centered... maybe it's the right wheel asking for adjustment.
anyways...
toe can be set by adjusting tie rod length;
just loosen the locking nuts and twist the center tube to lengthen it, then relock the nuts.
no need to remove them from the pitman arm or the spindle linkages in order to do so.

once the wheels are perfectly parallel and straight (pitman arm centered)
check if the spindle linkages need adjustment.

with the seat removed
wind a few turns of string around each kingpin head,
then pull those strings back to the dead center of the rear axle,
to form a V
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with the steering (and more importantly: the wheels) straight,
the linkage should be inline with the string,
(the tierod connection bolt is what counts..)

instead of a piece of string, a line laser works even better,
if you have one, make use of that instead

if both are off (by the same 'noteworthy' amount)
chances are it's not the spindles made for that kart.
if only one is off, indeed it might be bent.
if both are on (or off by a not noteworthy amount)
your only problem is spacing of the hubs really.

'sid
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Old 10-12-2019, 02:09 PM
turnleftandgasit turnleftandgasit is offline
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Margay did make offset karts. We raced them on dirt.
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Old 10-12-2019, 07:27 PM
zbillz zbillz is offline
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Upon further review, I do see the spacers that you guys are talking about. Looks like I may be able to move the spacers around on the right hub to get more inside tire clearance.
Looking closer at the spindles, one if them is either bent(no sign of any damage though?) or different than the other like you said.
The angles are definitely different.
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Old 10-13-2019, 05:26 AM
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itsid itsid is offline
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frankly I'm not sure those spindles are actually made for that kart...
usually kart mfgs take care to keep the tierods straight and parallel...

that front is 90% a Margay PantherX (minor differences)
would you mind to show us the rear of it?
(the engine unfortunately obscures all the important bits)
so theic from the right isn't helping

Quote:
Originally Posted by turnleftandgasit View Post
Margay did make offset karts. We raced them on dirt.
Margay doesn't list any offset kart, not a recent mdoel, and not in their vintage model list.
And sure that doesn't mean they never tried that BS ...
but since maaany people mistake other karts for Margays quite frequently
(coyotes for example.. which almos exclusively made oval karts)
I'm still a tiny bit unsure if Margay made ovals at all
But that's not the point of this thread, is it?

it's how to tackle the spindle issues OP has.
And since he thankfully has a straight rail chassis to deal with ...
we don't need to care much about
"cannot turn right properly - pretzels"

Once we know make and model a set of proper spindles should help
else some measurements will be required to reweld the linkages.
(spindles are mostly cheap so maybe that's the better fix *shrugs*)

'sid
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Old 10-14-2019, 03:13 AM
turnleftandgasit turnleftandgasit is offline
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https://www.margay.com/component/con...triker-x1.html

---------- Post added at 03:06 AM ---------- Previous post was at 03:03 AM ----------

Notice the different caster degrees listed in the ad. This is very common on dirt oval karts. This is the problem I'm having with modifying my Polaris, all kart people I have to bounce ideas off don't know a kart can turn right.

---------- Post added at 03:13 AM ---------- Previous post was at 03:06 AM ----------

I raced in the mid 90's. I was one of the last karts to win locally with a straight up chassis. I had to have Nationals level motors to win locally. Had to out drag them down the straight away because I couldn't roll the corners with them.
Margay was just losing their market dominance. Buller, Ultramax and others were just getting up and rolling.
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Old 10-14-2019, 03:36 AM
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oh indeed an oval Margay chassis.. must've missed that (selective perception quite possible)
the american habbit of going just round in circles (excuse me.. ovals) is the most boring thing I could imagine in racing..
A kart can turn right rather well.. that pretzeled abomination of a kart made specifically to run on left turn only tracks can 'steer' right.. but that's about it really

But it's luckily still a straight rail OP has to deal with so let's stay on topic.

'sid
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Old 10-14-2019, 07:54 PM
zbillz zbillz is offline
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Would rather relocate one of the spacers to the inside of the hub on the right side than reweld.
Easiest way to fix?

Looks like replacement spindles are around 100 dollars, if I could find the correct ones.

Still need to add a couple of teeth on rear sprocket to change the "CRAPTACULAR" overdrive ratio. Been using that word ever since I heard it from you Sid. Thanks again!
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