Tire Wear (More inside or outside?)
 

So I have a set of old RA1's (yes old) that have one edge worn significantly more than the other. These didn't come off my Miata (I'm a poor tire beggar!)

What I'm wondering is, should I put these on my Miata with the worn edge inside or outside? Here my Miata setup:

- koni yellow, 550F / 340R
- hollow RB bar up front, no rear bar
- ~1.5 front camber, 1.25 rear camber
- zero toe front/rear

Thanks

if you run too much camber, put that edge on the outside.

if you run too little camber, put it on the inside.

I am guessing that it is difficult to get 'too much' camber at ~12.75" ride height and stock arms. So put the worn edge on the inside?

Tim

just a quick note.....you should be running more rear camber than front and a little bit of toe in on all four ends for handling purposes.

I think with the camber you're running, put them inside

I'd say what is more important to consider is how much toe you're running. Thats the true killer of tires (as far as the inside/outside argument). You probably still want to run the worn edge on the outside regardless though.

I've heard that running tires in the incorrect rotation direction periodically will help them wear evenly as well.

You are just flat out wrong and must be called out. I'll let someone else take it from here.

lol I'm going by what other people have told me. My alignment is setup for autox, by what others have told me.

Front:
-1.1 camber
5 caster
1/32" toe in

Rear:
-1.75 rear
1/32" toe in

I'd actually like to know where I'm wrong so I can change it though....

I run a lot more rear than front, by memory its about 2 front 2.5 or 3 deg camber rear.

Dann

Let me try. (From 949 site):

>=12" front ride height (measured hub center to fender)

>=4.5" front ride height measured at forward most straight section of pinch weld with 205/50/15 or 225/45/15 tires

Front camber: -2* (or as close as you can get to it)
Caster: +3.75 to +4.25*
Front total toe: 0

Rear camber : -1.8*
Front total toe: 0

<=12.0"

3.75~ 4.25" front ride height measured at forward most straight section of pinch weld with 205/50/15 or 225/45/15 tires

Front camber: -2.8* (or as close as you can get to it)
Caster: +2.75 to +3.5*
Front total toe: 0

Rear camber : -2.5*
Front total toe: 0




Works for me (I use the second setup)..

PS, I'd mount the worn edges on the "outside".

Thanks guys, it really seems like it is a bit of a crap shoot on what side to mount the worn edges. I don't really have a bunch of camber and no toe, so inside wear should be low.. but there is also good camber gain through the travel so outside wear should be low as well.

So relatively even wear.. which means these tires won't last me all that long, ha (worn edges will wear too.. eventually cording).

Thanks

Get more camber and put the worn edges on the inside always.

Curious as to why worn on the inside? I try and get even wear, but always end up with slightly more wear on the insides. All the ax crew usually end up flipping the tires on the wheels to get the worn insides to the outside to extend life..

plz edumacate me.

the toe in will make it twitchy. Ok for AutoX but not for high speed stuff.

~12" ride height:
Rear camber: -2.0
Front camber: -2.2
Front Castor: 5.0
Rear toe-out: +0.125"

More camber means there's more weight resting on the inside edge of the wheel. More weight on it means more wear.

Uh yeah, I get that. The question was why would someone mount used tires with the worn edge on the inside edge. Try and keep up.

btw, you run more neg camber on the rear than front? :giggle:

Had it backwards, -2.2 is front and -2.0 is rear :giggle:

And I know that, of course I knew that...

I still don't understand what more rear camber is bad...my alignment setup is for autox. I spoke to a couple of auotx vets and they said my setup was a good streetable autox alignment

With a less than optimal setup you might be camber limited and wear the outer shoulders harder (yeah, I know you leave some perf on the table this way but hey, we all started somewhere), then there is nothing wrong in putting the most rubber where the wear is the hardest.

Back in my learner years I ran a 03 with just Yellow Konis and "old FM-springs". I needed to flip the tires twice to make the most of the rubber. With the modified LCAs (moved lower ball joint) and the -3.2 I run now the wear is even and I can just move wheels according to the wear at the track (LF is always punished the most on our tracks).

Do not let spitefulcheerio do your alignment.