[BXL4]

This will be my first performance car in many years and the first since the common practice of putting such relatively narrow tires on the rims that you have to worry about curb rash. Is this primarily an aesthetic preference or for cornering?

Where I live, the roads are cr@p and drivers bad enough that you really want to park close to the curb.

It seems that currently popular tire/wheel combos aren't so good for this situation.

As always, thanks to the Forum members for their knowledge and wisdom.

[tiltmode43]

I believe you are referring to 'stretching' the tires, or putting a tire that is slightly narrower than the wheel, on said wheel. This would be 98% aesthetics; there may be a small number of occasions where a minimal stretch will be used to increase sidewall stiffness, thus improving responsiveness and reducing deflection, but this is not always the case.

In general, the main thing to look out for is to whether the tire size chosen for any given wheel conforms to the tire manufacturer's recommended wheel widths. Any given tire size will have a range of acceptable wheel widths it will fit; this information is readily available on any tire manufacturer's website or often tire retailer websites such as www.tirerack.com.

Stay within manufacturer recommended specs and you will be good. That said, doesn't hurt to go with a wider tire option when available!

[BXL4]

I've seen the "stretching" but that wasn't what I was referring to.

I believe that every tire/wheel combo from the BMW factory will scrape the wheel in almost any circumstance when the tire were to rub however gently against the curb.

On a 225 tire mounted on an 8" rim would seem to be 10mm narrower than the tire, but it is the "overall rim width" that is the important figure when it comes to curb contact and generally, overall rim width is an additional 30mm or 1.5" greater making the wheel, not the tire the "curb feeler."

I'd like a less costly solution.

[tiltmode43]

Originally Posted by BXL4

I've seen the "stretching" but that wasn't what I was referring to.

I believe that every tire/wheel combo from the BMW factory will scrape the wheel in almost any circumstance when the tire were to rub however gently against the curb.

On a 225 tire mounted on an 8" rim would seem to be 10mm narrower than the tire, but it is the "overall rim width" that is the important figure when it comes to curb contact and generally, overall rim width is an additional 30mm or 1.5" greater making the wheel, not the tire the "curb feeler."

I'd like a less costly solution.

This could be considered a very minor stretch present. Of course all within manufacturer spec, so it wouldn't be a safety concern. You are correct about wheel width, however, as a wheel will typically be 1" wider than bead seat width ('advertised' width).

Generally, lower profile tires on larger wheels will increase the likliehood of wheel-curb contact. There is less sidewall bubble and the difference between wheel width and tire width has a greater width (length of sidewall) to distribute. For example, a 225/35/19 on 19x8.5 will not protect the wheel whereas a 225/50/16 on a 16x8.5 would likely protect the wheel.

As far as a 'solution' to this, the only real options would be A) Wider tires or smaller wheels w/higher profile tires or B) Be a bit more cautious when parking near curbs.

Long story short, the widespread use of 18", 19", and sometimes even 20" wheels on factory vehicles causes this problem. I know my 17" factory wheels & tires would have sufficient curb protection but they look a bit too small for the car's body size.

[bmwmmm]

If scraping the rim is your concern there are some tires that have a safety feature so that the tire hits the curb instead of the whell. If you look at the tire mounted to the wheel you'll see that the tire is not flush with the edge of the rim but is about 0.5'' out. You can still scrape the wheel with these if you are too agressive but it will help.

[BXL4]

Originally Posted by bmwmmm

If scraping the rim is your concern there are some tires that have a safety feature so that the tire hits the curb instead of the whell. If you look at the tire mounted to the wheel you'll see that the tire is not flush with the edge of the rim but is about 0.5'' out. You can still scrape the wheel with these if you are too agressive but it will help.

THAT sounds interesting. Can you name the brand and model? I think that would be the answer to my concerns. Thanks for your help.

[richb811]

Originally Posted by BXL4

THAT sounds interesting. Can you name the brand and model? I think that would be the answer to my concerns. Thanks for your help.

Michelin Pilot Sport and PSS have a small rim bead protector on them. Its not a full system like some tires though but it still looks good aesthetically.

Conti DW's I believe as well.