Low profile tires and bent rims

[JHZR2]

To a. Great extent I don't care about the tires... They are an expendable item, even if expensive. But with all the potholes, I do care about the wheels themselves. My older cars take 14-15" tires with big sidewalks, hopefully no issues. My truck, nbd. But the 16-18" wheels we have are another story.

So, what's the biggest contributing factor to bent wheels? Does running eft tires with their overly stiffened sidewall help prevent? Is it merely a function of tire pressure? Of course in the other thread about thin sidewalls, we discussed how they are a ratio, which feeds into this.

But practically speaking,what can one do to prevent? I'm most interested in if run flat tires inherently offer better protection? I'd be willing to scrap rfts tires and take a risk if it means a superior tire, but if rft tires protect rims better, I may stay with them for that very reason.

 

[Brybo86]

I think the best way to avoid a bent rim is a close eye on the road ahead, but I agree these low profile tires aren't helping anything

 

[Jeffs2006EvoIX]

One reason for bent rims is poor quality. Second reason people not keeping propper tire PSI. Third cheapy tires with weak side walls.

No tire or rim is full proof. Keep that in mind. You hit the right pot hole at the right speed and your s c r e w e d no matter what.

Having quality stuff just helps.

Run flats do indeed have stiffer side walls but are not always best for all applications. Most summer high performance tires have stiff side walls too.

There are pros and cons to everything. Watch your speed and use quality bits usually prevails.

Jeff

 

[Rolla07]

Originally Posted By: Jeffs2006EvoIX
One reason for bent rims is poor quality. Second reason people not keeping propper tire PSI. Third cheapy tires with weak side walls.

No tire or rim is full proof. Keep that in mind. You hit the right pot hole at the right speed and your s c r e w e d no matter what.

Having quality stuff just helps.

Run flats do indeed have stiffer side walls but are not always best for all applications. Most summer high performance tires have stiff side walls too.

There are pros and cons to everything. Watch your speed and use quality bits usually prevails.

Jeff


+1

I am using XL load rated tires. I heard they have stiffer sidewalls too..

 

[AboutTires]

Runflats can actually make the problem worse by transmitting more of the impact to the wheel.

 

[The motor guy]

Keep the tire pressure up and it should be fine. I always see low profile rims and just about everyone has underinflated tires.

 

[rationull]

This is the biggest reason I don't like the trend toward lower profile tires on bigger wheels in all kinds of cars. If I bend a rim on my car (17" wheels with 45 series tires) I'm going to seriously consider replacing the wheels with 16" steelies and getting taller tires, even though it's a performance car.

 

[KitaCam]

After increasing wheel size from 15 to 17 and reducing aspect ratio from 65 go 55, I have increased PSI from 34 (itself an increase over the OEM spec of 29) to 40psi up front/38 at rear.

...dirt patches on tread tell me that's about right.

 

[HTSS_TR]

17" wheels with 45 series tires is not "low profile", 2013 family sedan Mazda 6 has 19" wheel option, I don't know if it comes with 35 or 40 series tires.

We don't have problem with potholes in So Cal, but I still inflate the tires, front and rear, about 2-6 PSI above door placard and I think it helps protecting the wheels.

 

[spasm3]

Low profile is just not practical for rough roads . They look nice and do handle well. but on a daily driver , I prefer 15 inch wheels with taller side walls, I think the ride is smoother too. I have two sc1 saturns, granted my son's has worn suspension. The 02 has steelies with 14 inch tires (185 65 14), his has 15 inch geartooth saturn wheels( 195 60 15). The steelies ride better than his car ever has, his does handle better. There is probably only an inch difference in sidewall height (the 14's are about an inch more sidwall height) but i can tell a difference.

 

[rjundi]

My wife my virtue of MA roads hits nasty potholes occasionally with her Legacy GT 8yrs old/165k with 215/45/17 wheels. The tires all have been XL if that matters.

Subaru must have spec'ed some really tough wheels she hit two nasty potholes and raised manhole so hard that we have had two tires bubble or split at different times. One brand new so Continental replaced under free road hazard from them. Thankfully the other at end of life. Subie has a nasty requirement of all four tires match closely.

 

[chefwong]

A sharp eye.

Rolling on 315/35........this year. Decided not to swap winter tars.
Made sure PSI is bumped a bit higher than normal.

OK during morning, rushhour - as all the cars crawl when we hit stretches of pothole hotmess.

Dangerous to drive at night as some roads are littered with them and you can't catch them in time

 

[Traction]

Seem like almost half the cars I change tires on with 55 series or lower profile have a least one bent wheel and when is it 2 they are on the same side that hit the same hole. I really miss the old cars that rode so smooth on any road, and never had bent wheels. Nobody complained about how bad the roads where then, because the cars could take a bump and you wouldn't even feel it. Cars today it is all about handling and looks, but really not designed for the rough roads. A 73 Grand Marquis is much faster and better handling on a rough road that a C6 Corvette.

 

[CapriRacer]

JHZR2,

I think you're looking for some practical advice - right?

As has been mentioned, inflation pressure is important. What inflation pressure does is stiffen the tire, providing more resistance against the impacting object. In theory, you'd want only enough inflation pressure to prevent the tire from bottoming out (after accounting for load carrying capacity.) The problem here is that there is always a pot hole large enough to overcome this.

So the best you can hope for is reducing the risk.

The other half of the equation is that increasing the inflation pressure means the tire itself becomes more prone to impact damage.

The physics of impacting objects applies here - much like those games where people build a device to prevent a broken egg when dropped.

Those devices depend on slowing the egg down gradually - and in the case of tires, wheels and potholes, we are talking about sidewall height. Yup, if can afford to do so, the largest diameter tire mounted on the smallest diameter wheel is the way to go.

Yes, increasing sidewall strength will help. So, yes, RunFlat tires would be helpful. Just be aware that they are not immune - nothing is.

Other bits of advice? Soft springs, soft shocks both work until the suspension bottoms out. Then a soft bump stop would also help - but if the suspension is bottoming out, then all of that is for naught.

Ya' see, it's a compromise - and one hard to get right without adequate testing. And even then, nothing is immune. Wheels have been bent since they were invented. I'll bet some ancient Egyptian complained to his chariot maker about it.

 

[Kira]

Lower profile tires will go down in history as a foolish design ploy foisted upon the car customer. While someone may like the look and feel of them, having them mounted on a car should be a choice.

Does "forcing" anyone to buy a more vulnerable, more expensive, more rapidly wearing tire sound at all fair to you?

"Oh, premium, fancy wheels (misleading terminology) help sell a car. Criticizing them is hippie economics!"
Nonsense, low profile tires are simply wrong in many applications and shouldn't be flooded into a market.
Whether you like, dislike, desire, can afford or even know about their attributes is immaterial.
They're not a smart buy, they're a luxury item. Kira

 

[A_Harman]

We have a t-shirt in Michigan that says:
"No, I'm not driving drunk, I'm dodging potholes."

The roads here get noticeably worse after every snowstorm & snowplow cycle. The potholes get bigger and bigger, and grow together until you're driving over nothing but moonscape. Add to this weeks of near-zero temperature and the frost heaves that result, and I don't want to drive my Camaro faster than 30 mph.

We only have two seasons in Michigan: winter and road construction.

For winter tires, I'm driving on 225-55-16 Michelin X-Ice 2's on the OE aluminum wheels. Their sidewall height is identical to the original summer tires that came on the car. But I have hit some vicious potholes this winter, one of which caused my CD player to completely skip tracks. I've been thinking of putting on a set of 60-series tires when time comes to replace my current ones. Another 11 mm of sidewall height would be good for pothole protection and giving the car more ground clearance.

 

[JHZR2]

Originally Posted By: Kira
Lower profile tires will go down in history as a foolish design ploy foisted upon the car customer. While someone may like the look and feel of them, having them mounted on a car should be a choice.

Does "forcing" anyone to buy a more vulnerable, more expensive, more rapidly wearing tire sound at all fair to you?

"Oh, premium, fancy wheels (misleading terminology) help sell a car. Criticizing them is hippie economics!"
Nonsense, low profile tires are simply wrong in many applications and shouldn't be flooded into a market.
Whether you like, dislike, desire, can afford or even know about their attributes is immaterial.
They're not a smart buy, they're a luxury item. Kira


Well I agree with that and have said it for years, but have been booed out by many on here because of the ability to have bigger brakes and better handling "for safety".

I fear as more and more of the bottom-barrel cars get these (trickle down) what is going to happen.




With the current potholes, I just want to be best prepared. My car with lowest profile wheels/tires has run flats, and holds air well, but I wanted to be sure I'm optimizing as best as I can to protect from damage as much as possible. It's all about how to spread the forces best upon impact, and whether rft tires do that better by taking it within the tire carcass, vs transfer of a point load to the wheel.... And then how pressure plays in. M

Thanks for all the inputs!

 

[leeharvey418]

Originally Posted By: HTSS_TR
2013 family sedan Mazda 6 has 19" wheel option, I don't know if it comes with 35 or 40 series tires...


You're thinking of the 2014 Mazda6 that comes with 19" wheels on most models - and it comes with 225/45R19 tires. That's the same sidewall height that they've been putting on every Mazda3 with 17" wheels (205/50R17 tire size) that they've ever built, and that's a whole lot of cars.

 

[sparky123]

I have to agree Kira. I remember when looking at Mazda 5's the Sport and Touring version came w/different tire sizes. The 17's on the Touring I did not like at all. (From work a co-worker had some choice words for the 17's she had on her Mazda 5!) I looked into the new BWM's, all have run flats! (No spares as well I believe.) No thank-you for me.

 

[IndyIan]

I've never had run flats, but aren't they kind of a nasty tire? Noisy, transmits lots of vibration, expensive? Going to a 1" smaller rim seems like it has lots of advantages to run normal tires, with the exception of needing some sort of spare.
I seem to recall that audi was supplying very thin spares, maybe getting one of those to put in the trunk would work?