alignment changes v.tires

[Junkie Mod]

So, Tex and I are having a bit of a debate on AIM.

He thinks that changing your tires can change your alignment. Meaning, if you go to wider/shorter tires than you currently have, your alignment will change.

I think that as long as you have the same size tires on all 4 corners before and after, the alignment should stay the same. You can change what tires you are using, they just need to be the same on all of the corners. The *ideal* alignment might change, because you might want less camber with wider tires for instance, but the specs of the alignment shouldn't.

So, which one of us is right?

[Tex Arcana]

Fgt, you might want to mention that you're going from 195/60-14 tires/wheels to 205/50-15, as well as going from Costco Shitbox tires to somethign better, so the actual tire diameter and tread width can change fairly significantly.

My point is that, by going to a totally different brand and size tire, you run the risk of having the diameter off significantly enough to make the alignment for the shitbox tires wrong for the good ones; and if you eqat up the good ones in 10k like you have the shitbox tires, you'll be out the good money for good tires.

SEE??? Better safe than sorry.

[eighteen_psi]

If the diameter changes more than a negligible amount, you need to re-align.

[Junkie Mod]

Originally Posted by eighteen_psi

If the diameter changes more than a negligible amount, you need to re-align.

what alignment specs is changing the diameter going to effect?

[dvq]

Tire diameter and width won't change alignment specs, period.

[[H]ard|On]

Well it may change but not worth $70 change, IMO

Even after I changed struts I didn't get an alignment till way after (do you think that changed it? ) and it was fine, the tires didn't die or explode or wear weirdly...

[Tex Arcana]

Originally Posted by [H]ard|On

Well it may change but not worth $70 change, IMO

Even after I changed struts I didn't get an alignment till way after (do you think that changed it? ) and it was fine, the tires didn't die or explode or wear weirdly...

You got lucky, because worn struts can change your camber, and if you align to compensate for them, then replace them, then your camber is too positive, and there goes your tires.


Gotta take into account he's wanting to do more than just wheels/tires, as well: springs were mentioned, and that can make a difference as well.

[Tex Arcana]

Originally Posted by danvuquoc

Tire diameter and width won't change alignment specs, period.

Not the specs, no; but the actual geometry of the suspension can change with the change of wheels/tires, especially offset and diameter.

[Junkie Mod]

Originally Posted by Tex Arcana

You got lucky, because worn struts can change your camber, and if you align to compensate for them, then replace them, then your camber is too positive, and there goes your tires.


Gotta take into account he's wanting to do more than just wheels/tires, as well: springs were mentioned, and that can make a difference as well.

if I do suspension I'm gonna do more than just springs

and yes, if suspension is changed then you need to do an alignment after.

[Junkie Mod]

Originally Posted by Tex Arcana

Not the specs, no; but the actual geometry of the suspension can change with the change of wheels/tires, especially offset and diameter.

diameter isn't going to change anything

[dvq]

Originally Posted by Tex Arcana

Not the specs, no; but the actual geometry of the suspension can change with the change of wheels/tires, especially offset and diameter.

Let's define all of this as geometry. "Specs" are static geometry -- or "alignment". When suspension moves then you get dynamic geometry. That I will admit will be affected, but no amount of alignment changes will "fix" any effects of the dynamic geometry due to bigger wheels/tires.

[Tex Arcana]

Originally Posted by Junkie Mod

diameter isn't going to change anything

actually, going smaller will change the scrub radius, by making it larger, which will change the dynamic forces on the tire, the spindle, and the rest of the suspension; it will also change how the braking forces impact the suspension, sometimes negatively. You cannot change the scrub radius without changing the spindle itself; but a good alignment guy can compensate for the scrub forces by changing the caster, camber, and toe.

[[H]ard|On]

Around here, Id be lucky if the alignment guy can make my steering wheel point the right way.

Me: "Hey man, you didn't finish. My wheel is aimed to the left."
Him: "Esta bien, put it back on mang, i see what I do"
Me: "sigh"

[Tex Arcana]

Originally Posted by [H]ard|On

Around here, Id be lucky if the alignment guy can make my steering wheel point the right way.

tha's because you use carbwhore for your alignments.

[Lurker]

I shouldnt even be posting in this thread, but....... I think it wont make a difference if you are using a different tirr.