[sparkymarky]

2006 e90 330d m sport?


I had an alignment last year, which i notice on the printout says M3 (!) and after this i have gone through a set of rears (eagle f1's) in just 8000 miles....funny thing is its the centre that has worn out - i still have 4mm on inner and outer.

Given that these cars usually favour inner edge wear this seems abnormal (tyre pressures have not been overinflated - they have been kept at 37psi and so 2 psi under the stated 19" tyre pressure on the door jamb).

So, i have a link to m3 settings but does anyone have the settings for this car so i can take them back to the garage with me on monday?

[Digitalize]

I don't think it's possible for there to be a geometry setup that wears the middle only.

[jackstrath]

its not , to much wind in them imo

[sparkymarky]

Yea that's the most obvious thing, but I've never had them more than 37psi....and the new tyres I've just put on a month ago I'm running them at 35psi and they are showing wear in the centre as well....weird....

Going back with the original printout the garage did on their hunter machine which clearly shows it was set to m3 but I hear what you guys are saying...

[sparkymarky]

I reckon the camber is the cause I.e in laymans my wheels aren't sloping enough (be that pos or neg I can't remember) or to put it another way, they are 'too vertical' which may be as a result of the m3 settings which will have different bottom arms and camber settings. I'll upload the computer picture of the alignment they did in a minute.

[Shaun69]

My eagle f1's also wore in the middle, I was running -2 from door spec and now I'm running -5 (34f 36r). I think the door pressures are for runflats and probably don't need as much in normal tyres.

I went to wheels in motion who know what they're doing and they said by tracking was almost perfect

[sparkymarky]

http://i301.photobucket.com/albums/n...604_193312.jpg

[Aragorn30d]

Have you verified the pressure with an alternative guage? If you're always using the same one then it could simply be overreading?

[sparkymarky]

yep, i've used three different garage air machines this week and my own pressure gauge to verify.

[HighlandPete]

Don't forget not all middle wear is from over inflation, some tyre types suffer severe centrifugal growth. Driving speeds and acceleration rates can impact on how severe that growth is.

HighlandPete

[sparkymarky]

Thanks for the comments so far. just found this. Its for an e90 m sport rather than the m3 my car was set to. Clearly different settings. (I know it says for 18" wheels but searches seem to say that wheel size is irrelevant, its ride height thats important as the 19" has a lower profile tyre compared to the 18" and maintains an almost exact same rolling circumference so not to throw speedo out)

http://http://www.e90post.com/forums/showthread.php?t=78566

so up front: 1. Camber is way out. Both sides have around double max amt of neg
camber. (though not adjustable on e9x so how will rectify?)

2. TOE. JUST in lower limit
3. CASTOR - no idea as there is no data it seems on the oem spec sheet...

on the rear: 1. Camber - Below minimum. As i thought earlier, i do not have enough
'lean'. Too vertical, hence why middle of tyre is contacting more and wearing out wayyyy before inner and outer edges.
2. TOE - Below minimum toe of 0.1. I have little too much toe in/not
enough toe out

So event though the rear toe and rear camber are green (meaning ok) on the printout, they are only green because the incorrect baseline (m3) parameters were being used. They should be showing yellow and red for adjustment needed were the correct specs used at the time, it appears to me anyway.

will relay all this to the garage monday. To be fair though, the owner was helpful today when he heard of the potential problem and said he would 'hold his hands up if his guys have cocked up'....whether that means a free set of rear and potentially front tyres which i have just had/having to buy after 8000 miles remains to be seen.....

[Shaun69]

My car was aligned to theses figures which are different to the ones you've found.
There seems to be a bunch of different figures when you google it?

[sparkymarky]

Ah i think thats because you have an lci and those are the figures for an lci perhaps?

I know that lcis have a different track/et....

[Shaun69]

I have a 335d pre lci msport. I can't upload my alignment pic but it's the same as those figures. I went to wheels in motion who have a good reputation?

[HighlandPete]

Originally Posted by sparkymarky

..... on the rear:
1. Camber - Below minimum. As i thought earlier, i do not have enough 'lean'. Too vertical, hence why middle of tyre is contacting more and wearing out wayyyy before inner and outer edges.
2. TOE - Below minimum toe of 0.1. I have little too much toe in/not enough toe out.

So event though the rear toe and rear camber are green (meaning ok) on the printout, they are only green because the incorrect baseline (m3) parameters were being used. They should be showing yellow and red for adjustment needed were the correct specs used at the time, it appears to me anyway......

Why are you thinking the rear alignment settings (which are pretty good anyway for an M-sport) are responsible for the middle wear?

Extremes in camber and toe will influence inner or outer wear, depending on what is near or out of limits. If both tyre shoulders are pretty equal, that indicates a good alignment.

Middle wear is usually influenced by pressure setting, but as I said in the other post centrifugal growth is also a reason. Tyre weight, (heavy tyres are typically worse) speed and heat can influence the wear rate due to centrifugal growth.

What tyres are you running? What section/aspect ratio and what rim width are they on? How accurate is your gauge? Not a garage air point, but your checking gauge.

HighlandPete

[phozy888]

I've had the rear corrected but this should be a rough guide

[sparkymarky]

Originally Posted by HighlandPete

Why are you thinking the rear alignment settings (which are pretty good anyway for an M-sport) are responsible for the middle wear?

Extremes in camber and toe will influence inner or outer wear, depending on what is near or out of limits. If both tyre shoulders are pretty equal, that indicates a good alignment.

Middle wear is usually influenced by pressure setting, but as I said in the other post centrifugal growth is also a reason. Tyre weight, (heavy tyres are typically worse) speed and heat can influence the wear rate due to centrifugal growth.

What tyres are you running? What section/aspect ratio and what rim width are they on? How accurate is your gauge? Not a garage air point, but your checking gauge.

HighlandPete

Thanks pete. Like you i keep coming back to pressure. But now even only at 35psi, down from the previously mere 37, the new rear tyres are again wearing in the middle after a mere two months with no wear on the outer or inner.

I'm thinking (lack of) camber is playing a a part by reason of this simple analagoy. If you tilt your foot over to the left edge or right edge and walk on it like that eventually you would get pain and wear on that edge which is being leant on. Place the foot more vertical/upright and the load would be spread more onto the middle area of the bottom of the foot. To me this principle seems to follow with tyre wear I am experiencing - Add to this i have m3 camber settings, wherein camber is set LESS as the m3 control arms are longer and they ADD 0.75 of camber to the rears before anything is dialled in. Hence i have no 0.75 arms but unfortunately have had camber dialled out by using this m3 setting/approach of dialling out camber - hence a more vertical tyre. I may be wrong in my thinking of more vertical would potentially mean greater contact in the middle of the tyre but i cannot see why.

My tyre gauge is a modern expensive analogue works one - I use it on aircraft day in day out and it is regularly sent away for professional calibration due to my day job in the aviation industry (it always has to have a valid cal label).

The tyres running - eagle f1 assymetrics 265/30/19. Rim width 9.5, et35. Worn out in the middle in 8000 miles. inside and outside of the middle portion have about 4mm left. Now i have fulda sportcontrol - exactly the same thing appears to be happening already in the middle band.

I looked up centrifugal growth and understand the principal. I can do nothing about this though and cannot afford to just change tyres out. But yep if thats the cause then different tyres yet again next time will be the order of the day.

I could drop the rear pressures lower. BUT i am afraid of alloy cracking. I find a couple of psi more in the rear than the front gives better stability steering feel up front. Hence as the fronts are on 33 psi i would have to drop the fronts psi also and it is when you get around 30 psi that i fear alloy cracking (nothing scientific about this but speed bumps feel noticeably harder around this pressure). So i am reluctant to drop the rears past 35psi...

[zltm089]

Sorry to thread hijack....

but does anyone know where is the best place to have a proper alignment done?

I think they couldn't ajust the toe in for the fronts and said something about heating something...and it could damage other stuff...

and i said no.

I need a garage that knows bmw and wheel alignment!

[sparkymarky]

just taken some pics of the worn tyre and measurements across it, hang on will upload

[sparkymarky]

Ok so heres one of the rear tyres. worn after 8000 miles in the middle band. Looks like classic overinflation but only had 37psi. New one has 35 psi and is showing same pattern.

[phozy888]

Originally Posted by zltm089

Sorry to thread hijack....

but does anyone know where is the best place to have a proper alignment done?

I think they couldn't ajust the toe in for the fronts and said something about heating something...and it could damage other stuff...

and i said no.

I need a garage that knows bmw and wheel alignment!

I took mine here : http://www.goldenwheel.co.uk/

My front toe couldnt be adjusted too due to the tie rod seizing, they tried to heat aswell but it was stuck solid. I opted to change the tie rods and ends.

[AWSAWS]

Just dropped mine in for alignment. God be kind! $$$