M135i cracked wheel

[estoril]

I had the TPM alert on my M135i last week, pulled over and sure enough the tyre it identified was low on air, so I checked for obvious damage, nail etc but found nothing, after pumping up to about 40psi I stood and looked at it for a but but it seemed to be staying up so I tundled off to the nearest tyre depot...

...it's not a puncture they said but a crack....offside rear wheel with a visible crack across the edge of the rim...

So it went back to BMW, apparently they do an "ovality" check and if the wheel is running out more than 3mm it's your fault for hitting a pothole/curb to hard, if it's less than 3mm then they will consider replacing it. Mine was 0.03mm out and so they replaced it, I was relieved as they charge just short of £500 for a replacement.

I've heard of cars having issues with 19" wheels with runflats but not 18" with non-runflats.

 

[KnickeRS]

I had the TPM alert on my M135i last week, pulled over and sure enough the tyre it identified was low on air, so I checked for obvious damage, nail etc but found nothing, after pumping up to about 40psi I stood and looked at it for a but but it seemed to be staying up so I tundled off to the nearest tyre depot...

...it's not a puncture they said but a crack....offside rear wheel with a visible crack across the edge of the rim...

So it went back to BMW, apparently they do an "ovality" check and if the wheel is running out more than 3mm it's your fault for hitting a pothole/curb to hard, if it's less than 3mm then they will consider replacing it. Mine was 0.03mm out and so they replaced it, I was relieved as they charge just short of £500 for a replacement.

I've heard of cars having issues with 19" wheels with runflats but not 18" with non-runflats.

Glad to hear that you've had satisfaction from BMW though. I would have expected the non-run flat tyres to be damaged more easily that run flat equipped rims tbh. As nasty as run flats are, that steel side wall must dissipate a good deal of energy that otherwise might have struck the rims far easier than with.

 

[estoril]

Glad to hear that you've had satisfaction from BMW though. I would have expected the non-run flat tyres to be damaged more easily that run flat equipped rims tbh. As nasty as run flats are, that steel side wall must dissipate a good deal of energy that otherwise might have struck the rims far easier than with.

Interesting that you think the run flats would provide more protection, I had theorized that they make it worse by transmitting the impact to the rim as they are so stiff...

 

[KnickeRS]

Interesting that you think the run flats would provide more protection, I had theorized that they make it worse by transmitting the impact to the rim as they are so stiff...

Well possibly however I would have expected what is effectively two steel rings within both sidewalls of the tyre, to dissipate any shock around themselves rather than allow it to target the rim in such a way as to be able to make it crack.

I could be wrong, just took a considered viewpoint on this.

 

[PaulMc]

I always thought these run flats were worse for buckled wheels/ dented rims. I suspect the harder side walls are less forgiving and sends the shock of any pothole impact directly to the rim. The missus Mini has had 3 buckled wheels and coincidentally I have never had one. Her Mini Cooper S has the run flats, my cars never have.