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Is Even Foam Tire Wear a Sign of Proper Setup?

Is Even Foam Tire Wear a Sign of Proper Setup?

Old 02-20-2007, 10:43 AM
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Default Is Even Foam Tire Wear a Sign of Proper Setup?

I've been running a setup recently that seems to run very well however the foam tires are coning somewhat. If I try adjusting the camber to compensate for the tire wear it seems to throw the entire setup off. The camber is about 1 degree in front with 6 degrees caster and about 2.5 to 3 degrees in back.

So my question is should the tires wear evenly? If yes, should you adjust for even tire wear and change the setup from there as needed? How important is it? Is there a right or wrong answer?
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Old 02-20-2007, 10:44 AM
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Which tires are coning?
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Old 02-20-2007, 10:49 AM
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Originally Posted by A. Rhodes
Which tires are coning?
Both actually. The front on the outside a bit and the rear on the inside a little more.
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Old 02-20-2007, 10:53 AM
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Originally Posted by SlamMan
Both actually. The front on the outside a bit and the rear on the inside a little more.
You are running way to much rear camber, thus the coning. Try setting your car up with 2 in the rear, and adding a little more to the front, 1.5 to 2. That should take care of the coning issues, and should not really effect the overall set-up of the chassis.
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Old 02-20-2007, 11:04 AM
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Is even wear the sign of near optimum camber settings?

I had to reduce the camber on my fronts from 2 down to 1 to reduce inner wear. Doesn't seem to have hurt the handling.

On the other hand, on my pan car, only the outside of the fronts are wearing, and I have 2 degrees of camber, but very little reactive caster.
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Old 02-20-2007, 11:07 AM
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Originally Posted by Iceracer
Is even wear the sign of near optimum camber settings?
Yes
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Old 02-20-2007, 12:39 PM
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I have a question along the same lines.Overall tire wear during a run.Can this be used as an indicator of a good setup? Meaning,if during a run,I only wear .5mm and someone else on the samr track wears 1mm,is my setup better?should/could I use this as an indicator of the efficiency of my setup?or not? Thanks,Mario.
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Old 02-20-2007, 12:42 PM
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One thing to add is that having the rears wear slightly more on the inside is a good thing if you tend to chunk the outer edge of the rear tires. I always find the optimum camber to wear the rears flat and then add .25d more to ensure that they don't chunk as the grip comes up.

Andy's advice of 1.5d and 2.0d should be good. I've been running 1.5d/fr and 2.25d/rr for a long time now.

You stated that you tried to change the camber before and it had a negative effect on the handling. Please give us more detail on what you changed and how the car handled differently. This might point to another area of setup that needs to be rectified.
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Old 02-20-2007, 12:45 PM
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Originally Posted by lotus1
I have a question along the same lines.Overall tire wear during a run.Can this be used as an indicator of a good setup? Meaning,if during a run,I only wear .5mm and someone else on the samr track wears 1mm,is my setup better?should/could I use this as an indicator of the efficiency of my setup?or not? Thanks,Mario.
Less wear = more grip from the setup

A good rule of thumb is to get the least amount of wear possible. However, if your car is too *stuck* then it could cost you a lot of speed mid corner. You have to find the optimum grip where your car keeps a tight line, but doesn't scrub much corner speed.
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Old 02-20-2007, 01:05 PM
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I was running 1 degree camber on my 1/12ths on the new carpet track here. After a day of running, I had a slight coning of the front tires to the inside. I tried .5deg the next time out. The tires were wearing evenly but the car was now horrible to drive. Made the car hook hard on medium speed corners and had a really bad on power push. A few other guys had the same thing happen to them too. I don't think even tire wear is a definite indicator of how the car is working. If the car is fast and drives well, i wouldn't worry about uneven tire wear unless it is really severe.
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Old 02-20-2007, 01:34 PM
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Originally Posted by lotus1
I have a question along the same lines.Overall tire wear during a run.Can this be used as an indicator of a good setup? Meaning,if during a run,I only wear .5mm and someone else on the samr track wears 1mm,is my setup better?should/could I use this as an indicator of the efficiency of my setup?or not? Thanks,Mario.
Another thing that will effect this is the number of rights and/or lefts turns on a track. If the track layout has more of one type of turn, chances are the outside tire will wear more than the inside.

One thing to look at is the inside of your buddies body after a run. If there is a excessive amount of tire on the inside of the body, they are scrubbing more corner speed than you, wearing out their tires faster than yours.
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Old 02-20-2007, 01:49 PM
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Originally Posted by teamgp
You stated that you tried to change the camber before and it had a negative effect on the handling. Please give us more detail on what you changed and how the car handled differently. This might point to another area of setup that needs to be rectified.
I am running a setup on my 007 very similar to one of Paul L's latest. My camber was at 1d front and about 3 in back. I changed to 1.5 front and 2 in back and it made the car push on power and a bad hook off power. I hoping there may be a happy medium around 1.25 front and 2.5 in back.
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Old 02-20-2007, 02:21 PM
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Originally Posted by Jack Smash
I was running 1 degree camber on my 1/12ths on the new carpet track here. After a day of running, I had a slight coning of the front tires to the inside. I tried .5deg the next time out. The tires were wearing evenly but the car was now horrible to drive. Made the car hook hard on medium speed corners and had a really bad on power push. A few other guys had the same thing happen to them too. I don't think even tire wear is a definite indicator of how the car is working. If the car is fast and drives well, i wouldn't worry about uneven tire wear unless it is really severe.
Using tire wear to examine setup is a highly used process in scale racing and is applicable to RC. However, there are a lot of variables to consider and understand in order to use it effectively.

A few thoughts:

* Your goal should be to get even tire wear on the side of the car that takes the outside of most turns on the track. For most clockwise tracks it should be the left side. And vice-versa for counter-clockwise tracks (normally where Oval is run as well). The less used side will almost always have more coning on the inside edges.
* I always target a slight coning on the inside of the rear tires, to ensure that I don't chunk them. Something like, for every .3mm of wear on the outside edges I should have .4mm to .5mm of wear on the inside edges, depending on the amount of rear toe-in. More rear toe-in will create more coning on the rears inside edges.
* A track layout with a large sweeping corner at the end of the straight will almost always make the outside front tire wear more than the rest. Just rotate the front/rear tires from left to right after each run and true the rears down to match the fronts after no more than two to three runs to keep the diameters close.
* The front tires are the tricky part as camber gain and front end chassis roll play a big part in how they wear. In Jack's case above, reducing the camber, made the front tires contact patch increase when the power wasn't being applied fully (less chassis roll). However, when he went full on-power, the cars setup must be allowing a good bit more chassis roll, which effectively made the car ride on top of the outer edge of the tires. This reduced the front tires contact patch on-power.

In order to try to show the *trickiness* of using tire wear to adjust setup, here are a few options (not all) I would have considered in Jack's case:

- Less complicated: Adding more front camber gain by putting more angle in the front upper links (lower the inside or raise the outside) would raise the front roll center slightly and also increase the camber as the front end rolls. This might kill both birds with one stone if its enough of a change.

- More complicated (tried only if I already had maximum allowed angle in the front upper links) Adding front caster should cure the on-power push as it effectively increases the front camber as the wheel is turned to full lock. However, it may also cause the car to hook even more in the medium speed corners (neutral power). So I would probably have to either increase the front spring rate (alternatively stand up the front shocks more), raise the front roll center for less front end roll, or lower the rear roll center to plant the rear end more. I'd try the springs/shock angles first. If they don't work, then I'd raise the front roll center. I probably wouldn't try the rear roll center change as it will add more push on-power as well.

As Jack put it, if your car handles great and your satisfied with the lap times, then leave it alone and true the tires down after a few runs.
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Old 02-20-2007, 02:30 PM
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Originally Posted by SlamMan
I am running a setup on my 007 very similar to one of Paul L's latest. My camber was at 1d front and about 3 in back. I changed to 1.5 front and 2 in back and it made the car push on power and a bad hook off power. I hoping there may be a happy medium around 1.25 front and 2.5 in back.
Things like track surface(bumps)/grip/layout/, tire brand/compound, motor power, driving style, ambient temperature/humidity & even body type play a big roll as well though. Any differences in these may account for the larger gap between front & rear static camber than his Vegas setup (1.5d/2.5d) or even his Trackside setup (2.0d/2.0d).
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Old 02-20-2007, 04:10 PM
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I always adjust my camber so that the tires wear evenly. If you are coning, you are not using the full contact patch. That is why only part of the tire is wearing out. If you notice the coning and then try to compensate, be aware of the fact that you are only running on part of the tire until it wears down even. This may be causing your car to act erratic or "turn to garbage". Run them on the truer to even them out and then try again. You paid for 28mm, you might as well use it.
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