'Typical BMW camber'
Discussion
Upon replacing the set of MPSS I had on my M235i 6 months or so ago, the tyre fitter pointed out the excessive inner tyre wear on my rear tyres (down to the cord) and quoted the above (title)... After doing a bit of research myself, some agree with this, others blame alignment and/or tyre pressures.
Since then, I fitted a full set of PS4's due to the perceived better suitability to UK roads/weather as well as the fact they have firmer side walls to prevent premature inner rear and outer front tyre wear, I also had a full four wheel and toe/camber alignment done at the same time and upped my tyre pressures to a square 36psi.
6 months on, checking my rear tyres I've noticed the outer tyre walls on the front are looking a lot better than the MPSS' did... Same again for the inner rear tyres, however I couldn't help but notice the inside rears are approx 1-1.5mm lower than the outer rears. I'm not too worried as there's still plenty of tread either side and I have covered 7/8k miles already but just wondering if anyone with some experience in this or more knowledgeable than me can answer: Is this "typical BMW camber" at fault? Or is it something else...
Since then, I fitted a full set of PS4's due to the perceived better suitability to UK roads/weather as well as the fact they have firmer side walls to prevent premature inner rear and outer front tyre wear, I also had a full four wheel and toe/camber alignment done at the same time and upped my tyre pressures to a square 36psi.
6 months on, checking my rear tyres I've noticed the outer tyre walls on the front are looking a lot better than the MPSS' did... Same again for the inner rear tyres, however I couldn't help but notice the inside rears are approx 1-1.5mm lower than the outer rears. I'm not too worried as there's still plenty of tread either side and I have covered 7/8k miles already but just wondering if anyone with some experience in this or more knowledgeable than me can answer: Is this "typical BMW camber" at fault? Or is it something else...
If you view any specifications of a modern BMW specifically you will see a fairly “aggressive” negative camber on the tyre, and therefore the overall alignment of the vehicle. In effect the tyre is sitting / \ at the rear. This is fairly true equally of a number of other manufacturers.
So why do it?
Well in many cases there are obvious “limits” on tyre width to meet various legal requirements, although equally you might want the car to feel more “dynamic” or in reality actually have a greater level of grip more so during cornering.
By setting that level of negative camber into the car in a static state when the car is actually moving and critically cornering that negative camber will be pushed out to be more positive (not actually fully positive but more positive). This then in essence pushes more of the tyre into the road as it won’t in simple terms be / \ anymore but more | |. Giving you more grip and making the handling of the vehicle “better” or more “dynamic” if you will.
Like anything there is a downside to this is that in straight line you are running more on the inner edge of the tyre.
The next set of issues are more tyre related themselves – obviously the softer the tyre wall as part of the construction of said tyre then more likely the higher the wear will be, equally ignoring tyre pressures will therefore mean more of that inner tyre is in contact with road surface and producing faster tyre wear.
Another factor in this is tyre width, which in many areas has been driven by our desire to have larger wheels. These will in many cases show this negative camber more heavily purely down to the width of the wheel and tyre combination.
Overall the main reason for doing it is the above, but it shows itself in a number of ways and in areas that are indicative of owners not checking tyre pressures regularly. But equally owners should be more often reviewing the condition of their tyres more thoroughly. I would go as far to say that the rear tyres make this easy it simply means getting a surface to protect yourself and looking at the inner edge.
I suppose if you (and I have done this) desire less dynamic cornering as a negative consequence then you can go more towards a positive rear camber setup (not actually 0). The pay back though is a car that will feel inherently less dynamic, secure and composed during cornering.
In my experience by “less dynamic, secure and composed” I mean very nervous at the rear (possibly some might describe this as “loose”) end. In the rain this is not a nice feeling (for me at least) and therefore I returned to a more “aggressive” rear camber setup and the car was instantly more “planted”, and could handle being more aggressive in the corners and deciding to live with the “compromise” of greater inner tyre wear.
Pretty much picked this all up with alignment on my MX5 NC which had a way more aggressive rear camber than my 6GC, but I did so few miles in that it was not noticeable. Equally I combine this with saying that I use my Winter tyres which are significantly narrower than my Summer tyres, but even then the Summer tyres have not had issues such as this.
So why do it?
Well in many cases there are obvious “limits” on tyre width to meet various legal requirements, although equally you might want the car to feel more “dynamic” or in reality actually have a greater level of grip more so during cornering.
By setting that level of negative camber into the car in a static state when the car is actually moving and critically cornering that negative camber will be pushed out to be more positive (not actually fully positive but more positive). This then in essence pushes more of the tyre into the road as it won’t in simple terms be / \ anymore but more | |. Giving you more grip and making the handling of the vehicle “better” or more “dynamic” if you will.
Like anything there is a downside to this is that in straight line you are running more on the inner edge of the tyre.
The next set of issues are more tyre related themselves – obviously the softer the tyre wall as part of the construction of said tyre then more likely the higher the wear will be, equally ignoring tyre pressures will therefore mean more of that inner tyre is in contact with road surface and producing faster tyre wear.
Another factor in this is tyre width, which in many areas has been driven by our desire to have larger wheels. These will in many cases show this negative camber more heavily purely down to the width of the wheel and tyre combination.
Overall the main reason for doing it is the above, but it shows itself in a number of ways and in areas that are indicative of owners not checking tyre pressures regularly. But equally owners should be more often reviewing the condition of their tyres more thoroughly. I would go as far to say that the rear tyres make this easy it simply means getting a surface to protect yourself and looking at the inner edge.
I suppose if you (and I have done this) desire less dynamic cornering as a negative consequence then you can go more towards a positive rear camber setup (not actually 0). The pay back though is a car that will feel inherently less dynamic, secure and composed during cornering.
In my experience by “less dynamic, secure and composed” I mean very nervous at the rear (possibly some might describe this as “loose”) end. In the rain this is not a nice feeling (for me at least) and therefore I returned to a more “aggressive” rear camber setup and the car was instantly more “planted”, and could handle being more aggressive in the corners and deciding to live with the “compromise” of greater inner tyre wear.
Pretty much picked this all up with alignment on my MX5 NC which had a way more aggressive rear camber than my 6GC, but I did so few miles in that it was not noticeable. Equally I combine this with saying that I use my Winter tyres which are significantly narrower than my Summer tyres, but even then the Summer tyres have not had issues such as this.
Edited by Ninja59 on Tuesday 23 April 14:58
RobM77 said:
Have you had a four wheel alignment done? That should show your camber values and the spec for the car. I must admit, I've owned many BMWs over the years of varying spec and have never seen unusual tyre wear when running standard factory spec suspension geo.
Yeah! See my post above, had it done at the same time as fitted x4 new PS4's...Ninja59 said:
If you view any specifications of a modern BMW specifically you will see a fairly “aggressive” negative camber on the tyre, and therefore the overall alignment of the vehicle. In effect the tyre is sitting / \ at the rear. This is fairly true equally of a number of other manufacturers.
So why do it?
Well in many cases there are obvious “limits” on tyre width to meet various legal requirements, although equally you might want the car to feel more “dynamic” or in reality actually have a greater level of grip more so during cornering.
By setting that level of negative camber into the car in a static state when the car is actually moving and critically cornering that negative camber will be pushed out to be more positive (not actually fully positive but more positive). This then in essence pushes more of the tyre into the road as it won’t in simple terms be / \ anymore but more | |. Giving you more grip and making the handling of the vehicle “better” or more “dynamic” if you will.
Like anything there is a downside to this is that in straight line you are running more on the inner edge of the tyre.
The next set of issues are more tyre related themselves – obviously the softer the tyre wall as part of the construction of said tyre then more likely the higher the wear will be, equally ignoring tyre pressures will therefore mean more of that inner tyre is in contact with road surface and producing faster tyre wear.
Another factor in this is tyre width, which in many areas has been driven by our desire to have larger wheels. These will in many cases show this negative camber more heavily purely down to the width of the wheel and tyre combination.
Overall the main reason for doing it is the above, but it shows itself in a number of ways and in areas that are indicative of owners not checking tyre pressures regularly. But equally owners should be more often reviewing the condition of their tyres more thoroughly. I would go as far to say that the rear tyres make this easy it simply means getting a surface to protect yourself and looking at the inner edge.
I suppose if you (and I have done this) desire less dynamic cornering as a negative consequence then you can go more towards a positive rear camber setup (not actually 0). The pay back though is a car that will feel inherently less dynamic, secure and composed during cornering.
In my experience by “less dynamic, secure and composed” I mean very nervous at the rear (possibly some might describe this as “loose”) end. In the rain this is not a nice feeling (for me at least) and therefore I returned to a more “aggressive” rear camber setup and the car was instantly more “planted”, and could handle being more aggressive in the corners and deciding to live with the “compromise” of greater inner tyre wear.
Pretty much picked this all up with alignment on my MX5 NC which had a way more aggressive rear camber than my 6GC, but I did so few miles in that it was not noticeable. Equally I combine this with saying that I use my Winter tyres which are significantly narrower than my Summer tyres, but even then the Summer tyres have not had issues such as this.
Thanks for the informative response, it backed up most of what I've read myself with some good diagrams (/ \ + | |) So why do it?
Well in many cases there are obvious “limits” on tyre width to meet various legal requirements, although equally you might want the car to feel more “dynamic” or in reality actually have a greater level of grip more so during cornering.
By setting that level of negative camber into the car in a static state when the car is actually moving and critically cornering that negative camber will be pushed out to be more positive (not actually fully positive but more positive). This then in essence pushes more of the tyre into the road as it won’t in simple terms be / \ anymore but more | |. Giving you more grip and making the handling of the vehicle “better” or more “dynamic” if you will.
Like anything there is a downside to this is that in straight line you are running more on the inner edge of the tyre.
The next set of issues are more tyre related themselves – obviously the softer the tyre wall as part of the construction of said tyre then more likely the higher the wear will be, equally ignoring tyre pressures will therefore mean more of that inner tyre is in contact with road surface and producing faster tyre wear.
Another factor in this is tyre width, which in many areas has been driven by our desire to have larger wheels. These will in many cases show this negative camber more heavily purely down to the width of the wheel and tyre combination.
Overall the main reason for doing it is the above, but it shows itself in a number of ways and in areas that are indicative of owners not checking tyre pressures regularly. But equally owners should be more often reviewing the condition of their tyres more thoroughly. I would go as far to say that the rear tyres make this easy it simply means getting a surface to protect yourself and looking at the inner edge.
I suppose if you (and I have done this) desire less dynamic cornering as a negative consequence then you can go more towards a positive rear camber setup (not actually 0). The pay back though is a car that will feel inherently less dynamic, secure and composed during cornering.
In my experience by “less dynamic, secure and composed” I mean very nervous at the rear (possibly some might describe this as “loose”) end. In the rain this is not a nice feeling (for me at least) and therefore I returned to a more “aggressive” rear camber setup and the car was instantly more “planted”, and could handle being more aggressive in the corners and deciding to live with the “compromise” of greater inner tyre wear.
Pretty much picked this all up with alignment on my MX5 NC which had a way more aggressive rear camber than my 6GC, but I did so few miles in that it was not noticeable. Equally I combine this with saying that I use my Winter tyres which are significantly narrower than my Summer tyres, but even then the Summer tyres have not had issues such as this.
Edited by Ninja59 on Tuesday 23 April 14:58
I'm very happy with the way the car handles in all conditions since the addition of the PS4's on all corners @ 36psi (up from 32psi) and presumably the alignment too in comparison to the old setup. So yeah, I think I, like you, can live with the negatives of the aggressive camber setup as the benefits outweigh it.
I have just ordered a Michelin 12293 Digital Tyre Tread Depth/Pressure Gauge on good recommendation, so I'll be keeping a closer eye on both the pressures and the inner (rear)/outer (front) tyre wear more specifically.
95JO said:
Upon replacing the set of MPSS I had on my M235i 6 months or so ago, the tyre fitter pointed out the excessive inner tyre wear on my rear tyres (down to the cord) and quoted the above (title)... After doing a bit of research myself, some agree with this, others blame alignment and/or tyre pressures.
Since then, I fitted a full set of PS4's due to the perceived better suitability to UK roads/weather as well as the fact they have firmer side walls to prevent premature inner rear and outer front tyre wear, I also had a full four wheel and toe/camber alignment done at the same time and upped my tyre pressures to a square 36psi.
6 months on, checking my rear tyres I've noticed the outer tyre walls on the front are looking a lot better than the MPSS' did... Same again for the inner rear tyres, however I couldn't help but notice the inside rears are approx 1-1.5mm lower than the outer rears. I'm not too worried as there's still plenty of tread either side and I have covered 7/8k miles already but just wondering if anyone with some experience in this or more knowledgeable than me can answer: Is this "typical BMW camber" at fault? Or is it something else...
You will generally wear the inner rear and outer front edges moreSince then, I fitted a full set of PS4's due to the perceived better suitability to UK roads/weather as well as the fact they have firmer side walls to prevent premature inner rear and outer front tyre wear, I also had a full four wheel and toe/camber alignment done at the same time and upped my tyre pressures to a square 36psi.
6 months on, checking my rear tyres I've noticed the outer tyre walls on the front are looking a lot better than the MPSS' did... Same again for the inner rear tyres, however I couldn't help but notice the inside rears are approx 1-1.5mm lower than the outer rears. I'm not too worried as there's still plenty of tread either side and I have covered 7/8k miles already but just wondering if anyone with some experience in this or more knowledgeable than me can answer: Is this "typical BMW camber" at fault? Or is it something else...
PSS have a weird compound which highlights the issue more.
I am running -2.2 front degree camber and -1.5 rear and my tyres are wearing evenly.
I suspect you need an alignment as camber doesn't really wear tyres out much, it is generally toe.
Observe test conditions!
Front axle:
Total toe-in 0° 14' ± 12’
Adjustment total toe-in* 0° 14' ± 4'
Toe difference** single wheel between left/ right max. 12'
Camber
(Difference between left/right maximum 30')
- 0° 53' ± 30’
Adjustment camber* - 0° 53' ± 25’
Toe difference angle (difference between left/right max. 30’) -1° 33'
Castor angle (difference between left/right max. 30')
Front wheel offset 0° ± 15'
Maximum steering angle
‐ Inner cornering wheel approx. ° 39° 48'
‐ Outer cornering wheel approx. ° 33° 36'
Rear axle:
Total toe-in 0° 18' ± 12'
Adjustment total toe-in* 0° 18' ± 4'
Camber (difference between left/right max. 30') -1° 45' ± 25'
Adjustment camber* -1° 45' ± 5'
Geometrical driving axis 0° ± 12'
- Note: To minimise adjusting errors (measuring inaccuracies), use a narrower tolerance for adjusting toe/camber.
- Note: Toe difference front axle = criterion for steering wheel inclination
OP, can you post the sheet from the alignment?
Running the rear camber at the minimum allowed by BMW will help considerably. Many shops CBA to adjust the rear camber once they see it's within spec as it then means a toe adjustment is also needed. And then resettling the suspension. And then checking again. Anything in green is good enough, right?
Running the rear camber at the minimum allowed by BMW will help considerably. Many shops CBA to adjust the rear camber once they see it's within spec as it then means a toe adjustment is also needed. And then resettling the suspension. And then checking again. Anything in green is good enough, right?
AW10 said:
OP, can you post the sheet from the alignment?
Running the rear camber at the minimum allowed by BMW will help considerably. Many shops CBA to adjust the rear camber once they see it's within spec as it then means a toe adjustment is also needed. And then resettling the suspension. And then checking again. Anything in green is good enough, right?
I think this is the case, they definitely didn't let the suspension settle and check again - I think I left the print out in the glove box, although this was 6+ months ago now Running the rear camber at the minimum allowed by BMW will help considerably. Many shops CBA to adjust the rear camber once they see it's within spec as it then means a toe adjustment is also needed. And then resettling the suspension. And then checking again. Anything in green is good enough, right?
I'll check tomorrow and post it if I still have it!Actually checked the rears with an janky old analog depth gauge earlier, looks like the outer rears are ~4/4.5mm respectively and the inners ~3.5/4mm, so not much out really. Still waiting on the more accurate depth gauge to be sure, as not too confident the gauge I used can be considered accurate
Hmm, there's no indication of what the figures mean. I'd expect to see three for each measurement: your car's value a) before and b) after along with c) BMW's recommended figure. I can only assume that the small black figures are 'before' and the green figures are 'after', in which case yes, you had way too much camber before. It's also unusual to refer to negative camber with a +ve sign, but we have to assume all values are -ve (as they are for all cars these days).
RobM77 said:
Hmm, there's no indication of what the figures mean. I'd expect to see three for each measurement: your car's value a) before and b) after along with c) BMW's recommended figure. I can only assume that the small black figures are 'before' and the green figures are 'after', in which case yes, you had way too much camber before. It's also unusual to refer to negative camber with a +ve sign, but we have to assume all values are -ve (as they are for all cars these days).
It's camber and toe.But camber as I said went cause the excess wear.
I dug out my alignment sheet for my m135i which I've done around 15k on the tyres including several trackdays as I said and have equal wear across with 5mm front and 4mm rear.
xjay1337 said:
RobM77 said:
Hmm, there's no indication of what the figures mean. I'd expect to see three for each measurement: your car's value a) before and b) after along with c) BMW's recommended figure. I can only assume that the small black figures are 'before' and the green figures are 'after', in which case yes, you had way too much camber before. It's also unusual to refer to negative camber with a +ve sign, but we have to assume all values are -ve (as they are for all cars these days).
It's camber and toe.95JO said:
Here’s the print out - I’m surprised I sill have it. I’ll hold my hands up, I don’t know if that looks good or bad... PH tell me more.
It looks like the rear to was excessive at +5mm total toe and was adjusted back to +2.50mm.
Camber was Left 1.28deg, Right 1.14deg. Adjusted to 1.46deg both sides, which is increasing camber, but still similar to xjay's and in line with what I could find on Google which 1.45deg
https://www.google.com/url?sa=i&rct=j&q=&a...
Thanks for the replies guys, I must admit though I'm still none the wiser really... It does look like my alignment print out is matched up similarly to the official BMW specs, not sure whether that's good enough or not though.
Do you think my current alignment is acceptable and shouldn't cause any excessive wear on my inner rears (or anywhere else for that matter)?
Do you think my current alignment is acceptable and shouldn't cause any excessive wear on my inner rears (or anywhere else for that matter)?
I had the same problem on my M235i - the original MPSS wore really badly on the edge, more so on the fronts.
At about 20k I fitted Eagle AS3s all round. Now at 60k and I still have the same Goodyears on the front - they are wearing perfectly evenly and lasting forever, which is annoying as I don't like them much. The back now has PS4s which seem to be wearing evenly too.
At about 20k I fitted Eagle AS3s all round. Now at 60k and I still have the same Goodyears on the front - they are wearing perfectly evenly and lasting forever, which is annoying as I don't like them much. The back now has PS4s which seem to be wearing evenly too.
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