Rear tire wear

[Dollma]

I have the inner edge of both rear tires worn down like the edge has been totally shaved off. I thought it was just one but I felt the other one and it is both of them. One is worn down to nylon belts looks like. The fronts look like they are just barely wearing the outside edges and does not seem bad. I am including a pic of the worst one on the rear and it is drivers side rear tire. The reason I am posting is I get confused with terminology. Is this a toe problem or camber? I am thinking tie but like I said I am having a problem with the correct terminology. And what should it be set at in rear when I do an alignment . -2.0 ??? Thanks for all the help.


2011 X5d

[Molez93]

Definitely looking like an alignment issue, although X5s are known to eat tires. I’ve owned a handful of E70s and never experienced similar rear wear.

[yco]

its too much camber.. too much negative camber to be precise..
it should be set very close to zero on negative side..

[mitch808]

Originally Posted by yco

its too much camber.. too much negative camber to be precise..
it should be set very close to zero on negative side..

Toe eats tires, camber does not.

I can have 1deg of toe eat tires faster than 3deg of camber.

As long as you get toe within 0.03 to 0.01, your camber is fine upwards of -2.0 on a street driven vehicle.

[yco]

Originally Posted by mitch808

Toe eats tires, camber does not.

I can have 1deg of toe eat tires faster than 3deg of camber.

As long as you get toe within 0.03 to 0.01, your camber is fine upwards of -2.0 on a street driven vehicle.

without checking the alignment of the car we can guess forever..

[Molez93]

Obviously, the alignment issue could be from failing/spent bushings. I had similar, but very even left & right, front inside wear last fall. Bushings on the lca and thrust arms were shot on both sides.

[tmvatlanta]

Originally Posted by mitch808

Toe eats tires, camber does not.

I can have 1deg of toe eat tires faster than 3deg of camber.

As long as you get toe within 0.03 to 0.01, your camber is fine upwards of -2.0 on a street driven vehicle.

This is correct. Set the toe as close to 0 as possible.

[Dollma]

So this was the readout when I got new tires yesterday. I told him to get the rear closer .01 .I argued with them and they said the toe could not be adjusted anymore. I asked if it physically cannot be adjust or if they would not adjust it further to zero. They said it physically could not it was further they could go.

I then proceeded to tell them that I am going to keep an eye on the wear of them and if it looks irregular I will bring back for new tires. He finally said they have a warranty but he would not replace them 10 times. I laughed.

Is it possible they could not be further adjusted and how do all numbers look!

[RL18]

Did you say they couldn't adjust the toe or wouldn't adjust the toe?

I've been told before that they wouldn't bring the toe down, but I told them to pound sand and do what I asked them because I'm paying for it.

If they couldn't do it I wonder if they make an adjustable toe arm for our e70s. My e90 had one available and I got toe to approx: .06 and the adjustment was simple. That worked wonders on my e90 for inner tire wear. And mind you my e90 has about -1.8 camber in the rear soooo it's not the camber eating tires. I'd probably add some more neg camber and get that toe to .06-.09.

[Dollma]

He Actually said he couldn't. But I'm not sure I believe him.

[SF07e70]

Previous settings were closer to 0 toe.

Although, the camber adjustment likely affected this, they lied to you and kept it in the green to be on the “safe side”.

The inner tire wear on the rear left tire seems due to underinflation and a bit of excessive negative camber.

[yco]

thanks for feedback Dollma..
based on the paper, you may feel more stable on steering wheel center with this setup now.. though i prefer toe-out on front for better cornering.. ideal is toe out on front, toe in on the back.. you have toe in on both axles now.. but more importantly you better keep on eye on rear tires some time to time and tire pressures.. since its already worn out on the inside, it can be risky in the future..

Originally Posted by RL18

If they couldn't do it I wonder if they make an adjustable toe arm for our e70s. My e90 had one available and I got toe to approx: .06 and the adjustment was simple. That worked wonders on my e90 for inner tire wear. And mind you my e90 has about -1.8 camber in the rear soooo it's not the camber eating tires. I'd probably add some more neg camber and get that toe to .06-.09.

E90 has less than 400kg static load on each tire with much narrower tire width according to X5.. you expect "similar" results but not the same.. -0.03 avg. toe's affect gets harder on tire cause of loads and camber according to the alignment paper.. we re talking about almost 600kg of static load each tire.. and almost 2 degree of camber on rear left tire which is the worst looking one.. when you add the loads it wont make the same thing happens on your E90.. im not even adding the higher center of gravity and harder weight transfers according to that.. and feeling the difference on 0.05 of toe on rear tires is impossible on the street.. unless you drag from positive to negative or negative to positive.. starting with each 0.10 car starts to react differently especially on hard braking like on a track day.. especially on front.. the rest only can be felt on tire wear if we re talking about less than 0.10.. assuming no slick tires are into play..

tires doesnt look feathered that much.. so for me it looks like a reason of excessive camber + toe out on rear.. if you take one of them out it d look differently..

[mitch808]

https://www.newtis.info/tisv2/a/en/e...rement/QEcQc5W

It can be done. Personally, I would have left the rear camber where it was. Adjusting the camber, messed with the toe, and its a balancing act to get them where you want... Most quickie alignment places don't have the patience nor skills to do it. Try Euro Classics in Dayton

[Dollma]

Sorry guys that alignment is with a new set of tires on it. I bought four new of the continentals dws6 that so many of the guys on here recommend!

Bottom line guys do I need to get the alignment redone at this time by someone who knows what they are doing or add alittle pressure like I have seen others say do? Or do both??

[mitch808]

Think of toe, when set wrong, scrubbing your tires, by dragging them around as they turn. They are pointing inwards "pigeon toed," or pointing outwards like a pregnant woman walking.

Camber is just more contact patch in one area, than the full face of the tread.

In that analogy, you can see how toe can kill tires faster than camber. Neutral setups, will have toe close to a value of 0.06 or smaller. Where as camber can be upwards of -2.0deg with little effect on overall wear. (Of course proper rotation is key, if possible in a non-staggered setup)

A setting of 0.1 as you have, is not awful, just lazy.. I would just watch em over time for wear at this point.

[RL18]

Originally Posted by yco

thanks for feedback Dollma..
based on the paper, you may feel more stable on steering wheel center with this setup now.. though i prefer toe-out on front for better cornering.. ideal is toe out on front, toe in on the back.. you have toe in on both axles now.. but more importantly you better keep on eye on rear tires some time to time and tire pressures.. since its already worn out on the inside, it can be risky in the future..

E90 has less than 400kg static load on each tire with much narrower tire width according to X5.. you expect "similar" results but not the same.. -0.03 avg. toe's affect gets harder on tire cause of loads and camber according to the alignment paper.. we re talking about almost 600kg of static load each tire.. and almost 2 degree of camber on rear left tire which is the worst looking one.. when you add the loads it wont make the same thing happens on your E90.. im not even adding the higher center of gravity and harder weight transfers according to that.. and feeling the difference on 0.05 of toe on rear tires is impossible on the street.. unless you drag from positive to negative or negative to positive.. starting with each 0.10 car starts to react differently especially on hard braking like on a track day.. especially on front.. the rest only can be felt on tire wear if we re talking about less than 0.10.. assuming no slick tires are into play..

tires doesnt look feathered that much.. so for me it looks like a reason of excessive camber + toe out on rear.. if you take one of them out it d look differently..

Thankyou for the detailed explanation. What would you recommend toe and camber specs be set at?

[yco]

Originally Posted by RL18

Thankyou for the detailed explanation. What would you recommend toe and camber specs be set at?

it depends on the car and the track.. but as a base setup to tweak afterwards as i ve said having slight toe-out on front and slight toe-in on the back give a better high speed stability and initial cornering performance..

for camber wise, you see on road cars suspension adjusted to have negative camber on the back (race cars have perpendicular rear tire angle) depending on the load of the car on rear and some slight positive caster with it.. especially VW cars start to have more positive caster more as ride height is lowered.. cause more load on rear tires means more rolling force on corners basically.. its for rear end stability.. but the point is having camber on front is the more useful one for avoiding understeer in the end.. depends on your driving style and track.. if the camber that doesnt let you use whole tire patch on corners it is useless.. you lose grip because of it.. best way to understand how much you need camber on front and rear is to measure the tire temps in 3 sectors of a tire after a session.. inner, mid and outer part.. so lets say highest temp is on outer edge means you may need more negative camber (assuming you re only tweaking the camber).. setting a car right is a tricky thing and its more complicated than it looks..

[RL18]

Originally Posted by yco

it depends on the car and the track.. but as a base setup to tweak afterwards as i ve said having slight toe-out on front and slight toe-in on the back give a better high speed stability and initial cornering performance..

for camber wise, you see on road cars suspension adjusted to have negative camber on the back (race cars have perpendicular rear tire angle) depending on the load of the car on rear and some slight positive caster with it.. especially VW cars start to have more positive caster more as ride height is lowered.. cause more load on rear tires means more rolling force on corners basically.. its for rear end stability.. but the point is having camber on front is the more useful one for avoiding understeer in the end.. depends on your driving style and track.. if the camber that doesnt let you use whole tire patch on corners it is useless.. you lose grip because of it.. best way to understand how much you need camber on front and rear is to measure the tire temps in 3 sectors of a tire after a session.. inner, mid and outer part.. so lets say highest temp is on outer edge means you may need more negative camber (assuming you re only tweaking the camber).. setting a car right is a tricky thing and its more complicated than it looks..

I was talking more on the x5 as a road vehicle. But I think this is still relevant for that too. Again thankyou for the detailed explanation