[moldcad]

Hello guys,

As some of you might remember, I have a set of BC Forged wheels and MP4S tires, ordered exactly to the specs of M235i 19" wheels&tires offered by Dinan (with 235/35 front and 265/30 rear). Yesterday - for the very first time since putting them on my car - I was unlucky enough to hit a very deep pothole with my right front wheel; the impact and trashing noise were so severe I was almost positive either the tire, or the wheel, or both couldn't possibly survive it (in fact, it was the most violent impact I ever had with any of my many cars during the 48 years of driving). Suspecting the worse (even though I didn't feel or hear anything abnormal with my steering wheel or the way my car was rolling after the hit), I pulled into the first city bus bay on my way in order to see what I was fearing the damage was - and to my great relief, I saw both the tire and the wheel at perfect order! Of course, such a superficial assessment in the middle of the heavy city traffic has not been enough, so I steered straight to my tire shop... The mechanic who knows me and my car took the wheel off the car and put it on the balancing machine to spin it and see how much it got out of shape - and to my disbelieve, the tire didn't have any visible damage (like a bulb or cut), and the wheel assembly rotated as if nothing ever happened - perfectly straight in both the radial and lateral directions...

What do you make of it? Was I simply lucky - or are the BC Forged wheels so much stronger than most other wheels (cause I'm 100% positive that were it the OEM 18" wheel, it would have broken, bent or both)... I realize it's still possible a bulb will appear on the tire with time, but am I right assuming that a forged wheel would either cracks or not - with any long-term hidden damage not highly probable?

Anyway: if it turns out after another 1,000 km or so that no visible damage develops, may I assume I'm good and safe? Opinions, please...

Piotr

[x233]

Lucky you.

If there had been any damage either to the wheel or the tire it would have been apparent right away. True forged wheels don't crack unless it's something extreme (not your case). They bounce and they bend if the impact is too much. If there is a damage to the tire (damaged sidewall) it's apparent almost immediately. It would have been apparent by the time you stopped by your tire shop.

So it must have been the suspension that took the hit. If your shocks are fine during the next couple of weeks (no oil leak and no other apparent damage) you should be fine.

[moldcad]

Yeah - considering the violence of the impact, i was lucky indeed. Will keep my eye on the shock; would you advise geometry check or - if the car drives as usually - it's not necessary?

Piotr

[x233]

Originally Posted by moldcad

Yeah - considering the violence of the impact, i was lucky indeed. Will keep my eye on the shock; would you advise geometry check or - if the car drives as usually - it's not necessary?

Piotr

Probably not. Unless you experience something unusual. Or, perhaps if you suspect it could be out of whack you might ask them to check to be on the safe side.

[Maynard]

You might also want to check your alignment, especially if you notice changes in how it tracks or a drop in mpg. I've had a few of those bone-crunching hits (there are some of those potholes on the highways around here) - have not damaged tires or the factory wheels yet, but I do need an alignment with just about every seasonal tire swap.

From what I've heard, it is often those indirect sidewall impacts -rubbing or grazing up on the edge of the hole or curb - that really tear up tires, and sharp edges like curbs that dent rims. Straight on impacts are a lot easier for the tire to soak up.

[aerobod]

I would also look for any distortion in the top of the strut towers, although it is quite hard to check on the F22 as they are half covered and you can't just lay a ruler over the top of them to check if they have become domed, but visually ensure that they look exactly the same left and right.

[moldcad]

Originally Posted by Maynard

You might also want to check your alignment, especially if you notice changes in how it tracks or a drop in mpg.

"Alignment" is the word I missed in my previous post, so I wrote "geometry" instead - but this is just my English limitations

Piotr

[Miata13]

If you're truly concerned about any tire damage, you may wish to consider having it dis-mounted and inspected from the inside....just a thought. You wouldn't want hidden damage to cause the tire to fail during any high speed run.