Bent Rim…stronger and lighter rims? I need advice

[Submarines]

What do you mean by that? Are you making the wheels??

Yes, I've penned 100+ designs across multiple brands, did engineering and supply chain management on cast designs across multiple factories and companies, and did a custom set for myself I ran the engineering analysis on; I own my own brand.

Lighter wheels isn't always better. impact loads are near instantaneous that the wheel doesn't have time to react. The tire generally pinches before it can even properly absorb it (resulting in a sidewall bubble). The reaction time of wheel to move away from a pothole is determined more by the shock compression/rebound valving, spring rate and suspension travel available.

Unsprung mass has to do more with turn in dynamics and overall handling/acceleration.

The cross sectional shear area is what matters the most in combination with the material strength (less so).

OEM wheels are built with a slightly higher safety factor, and mass produced so less weight optimization is done. You tend to see more damaged stock wheels simply because of the volume of wheels, as large as the aftermarket industry is, the vast majority of wheels on cars are OEM

 

[Ohiocruiser]

Yes, I've penned 100+ designs across multiple brands, did engineering and supply chain management on cast designs across multiple factories and companies, and did a custom set for myself I ran the engineering analysis on; I own my own brand.

Lighter wheels isn't always better. impact loads are near instantaneous that the wheel doesn't have time to react. The tire generally pinches before it can even properly absorb it (resulting in a sidewall bubble). The reaction time of wheel to move away from a pothole is determined more by the shock compression/rebound valving, spring rate and suspension travel available.

Unsprung mass has to do more with turn in dynamics and overall handling/acceleration.

The cross sectional shear area is what matters the most in combination with the material strength (less so).

OEM wheels are built with a slightly higher safety factor, and mass produced so less weight optimization is done. You tend to see more damaged stock wheels simply because of the volume of wheels, as large as the aftermarket industry is, the vast majority of wheels on cars are OEM

Very impressive! So what whould you call the best around wheel for the car like stinger, at reasonable price point, of course. Something like the widest you can have for the tire or narrowest, straight spokes or concave, cast or flow formed. Does any of that play big role?

 

[Submarines]

Very impressive! So what whould you call the best around wheel for the car like stinger, at reasonable price point, of course. Something like the widest you can have for the tire or narrowest, straight spokes or concave, cast or flow formed. Does any of that play big role?

It's all down to personal taste and how much you're willing to spend.

My go to setup for the Stinger is 19x8.5 + 35 and 19x9.5+40 with 245/40/19 and 275/35/19 tires. You want to pay attention to the revs per mile when going staggered, get as close as possible, stock staggered setup is around 2 revs/mile difference if I recall correctly.

19x8.5+35 with 245/40/19 all around tends to be a safe bet as well. Little extra cushion doesn't hurt, speedometer is barely off.

Spoke design plays some role but it's too tedious to dive into each aspect since a well engineered wheel will be fine and it comes down to styling.

Flow form only effects the rear barrel, the front is still standard cast and will be the same strength as other cast wheels. Gravity cast tends to have a stronger face and Low pressure cast has a stronger barrel based on metallurgy cooling. Tilt casting (advanced gravity casting) is the best method available and employed by a handful of factories around the world.

Having a wheel from a good factory and a proper load rating matters the most. You can tell if it's good based on the import data of the brand (look up shipping records), you want to look for Taiwan, Japan, or Thailand. China tends to be very inconsistent (some really good, some really really bad).

 

[Ohiocruiser]

It's all down to personal taste and how much you're willing to spend.

My go to setup for the Stinger is 19x8.5 + 35 and 19x9.5+40 with 245/40/19 and 275/35/19 tires. You want to pay attention to the revs per mile when going staggered, get as close as possible, stock staggered setup is around 2 revs/mile difference if I recall correctly.

19x8.5+35 with 245/40/19 all around tends to be a safe bet as well. Little extra cushion doesn't hurt, speedometer is barely off.

Spoke design plays some role but it's too tedious to dive into each aspect since a well engineered wheel will be fine and it comes down to styling.

Flow form only effects the rear barrel, the front is still standard cast and will be the same strength as other cast wheels. Gravity cast tends to have a stronger face and Low pressure cast has a stronger barrel based on metallurgy cooling. Tilt casting (advanced gravity casting) is the best method available and employed by a handful of factories around the world.

Having a wheel from a good factory and a proper load rating matters the most. You can tell if it's good based on the import data of the brand (look up shipping records), you want to look for Taiwan, Japan, or Thailand. China tends to be very inconsistent (some really good, some really really bad).

Thank you for explaining! Didn't even know about different ways of casting wheels. Will do more reading on that topic.

 

[Volfy]

Lighter wheels isn't always better. impact loads are near instantaneous that the wheel doesn't have time to react. The tire generally pinches before it can even properly absorb it (resulting in a sidewall bubble). The reaction time of wheel to move away from a pothole is determined more by the shock compression/rebound valving, spring rate and suspension travel available.

Unsprung mass has to do more with turn in dynamics and overall handling/acceleration.

Incorrect.

The unsprung mass of the wheel/tire assembly (Mus in below diagram) is an integral part of the suspension system and, therefore, has every bit to do with how the articulation of the suspension system moves away from an impact. So do Kt (spring rate of tire), as well as Ks (coil spring rate) and Cs (damping factor).

A simply thought experiment will help visualize this. Imagine if you spend enough money to buy a set of wheel/tires that are practically weightless (Mus ~=0). How would the suspension system react to a sudden large increase in S (road undulation)? Well, beyond the initial compression of Kt (tire sidewall as a spring), yus will react almost instantaneously, because Mus is zero. This is good, because the sooner yus begins to move, the sooner Ks and Cs can be brought into play to help buffer impact force and absorb the impact energy.

Now then, wheels/tires obviously are never weightless. So, as the unsprung mass (Mus) begins to increase from zero, its inertia begins to increase, which means Mus will increasingly become reluctant to move upon initial impact, especially if the slew rate is very high (in the case of a large sharp bump in the road hit at high vehicle forward speed). If the wheel/tire is heavy enough, the impact will fully compress kt, resulting in a hard strike on the wheel rim, leading to likely wheel damage.

So in a scenario like this, lighter wheel is ALWAYS better... no if, else, or buts.

 

[Ohiocruiser]

Incorrect.

The unsprung mass of the wheel/tire assembly (Mus in below diagram) is an integral part of the suspension system and, therefore, has every bit to do with how the articulation of the suspension system moves away from an impact. So do Kt (spring rate of tire), as well as Ks (coil spring rate) and Cs (damping factor).

A simply thought experiment will help visualize this. Imagine if you spend enough money to buy a set of wheel/tires that are practically weightless (Mus ~=0). How would the suspension system react to a sudden large increase in S (road undulation)? Well, beyond the initial compression of Kt (tire sidewall as a spring), yus will react almost instantaneously, because Mus is zero. This is good, because the sooner yus begins to move, the sooner Ks and Cs can be brought into play to help buffer impact force and absorb the impact energy.

Now then, wheels/tires obviously are never weightless. So, as the unsprung mass (Mus) begins to increase from zero, its inertia begins to increase, which means Mus will increasingly become reluctant to move upon initial impact, especially if the slew rate is very high (in the case of a large sharp bump in the road hit at high vehicle forward speed). If the wheel/tire is heavy enough, the impact will fully compress kt, resulting in a hard strike on the wheel rim, leading to likely wheel damage.

So in a scenario like this, lighter wheel is ALWAYS better... no if, else, or buts.

I think he was talking about strength of the wheels. Depending on how the wheel is made it can affect different sections of the wheel. Everything else being equal, the lighter wheels will always be better.

 

[Volfy]

I think he was talking about strength of the wheels. Depending on how the wheel is made it can affect different sections of the wheel. Everything else being equal, the lighter wheels will always be better.

If it was stated in that way, I would absolutely agree. I think we are very fortunate to have a wheel designer telling his side of the story and relating his design philosophies. I think it's invaluable.

However, I did re-read the post judiciously several times, and he was specifically referencing unsprung mass as it relates to the other suspension components, similarly to what I described in my post #25. Except... he drew conclusions that were, well... at best, somewhat misleading, and, at worse, factually incorrect.

When one speaks from a self-professed position of expertise & authority, one owes it to him/herself - as well as the audience - to parley with a heightened level of propriety.

 

[Submarines]

Incorrect.

The unsprung mass of the wheel/tire assembly (Mus in below diagram) is an integral part of the suspension system and, therefore, has every bit to do with how the articulation of the suspension system moves away from an impact. So do Kt (spring rate of tire), as well as Ks (coil spring rate) and Cs (damping factor).

A simply thought experiment will help visualize this. Imagine if you spend enough money to buy a set of wheel/tires that are practically weightless (Mus ~=0). How would the suspension system react to a sudden large increase in S (road undulation)? Well, beyond the initial compression of Kt (tire sidewall as a spring), yus will react almost instantaneously, because Mus is zero. This is good, because the sooner yus begins to move, the sooner Ks and Cs can be brought into play to help buffer impact force and absorb the impact energy.

Now then, wheels/tires obviously are never weightless. So, as the unsprung mass (Mus) begins to increase from zero, its inertia begins to increase, which means Mus will increasingly become reluctant to move upon initial impact, especially if the slew rate is very high (in the case of a large sharp bump in the road hit at high vehicle forward speed). If the wheel/tire is heavy enough, the impact will fully compress kt, resulting in a hard strike on the wheel rim, leading to likely wheel damage.

So in a scenario like this, lighter wheel is ALWAYS better... no if, else, or buts.

You're overthinking and the example you gave is more for harmonic motion of shock/spring systems over uneven pavement (not a pothole) for ride quality (slow speed dampening).

Potholes are more of an instantaneous point load. Therefore you need to consider that the wheel doesn't move during initial contact as the tire gets crushed. Impact loading and physics are an entirely different beast since you have to assume zero movement in a small time space. You're also forgetting that the wheel doesn't magically transmit the energy through it's structure, the load is absorbed through the flange and barrel face and then through the spokes and central hub before the wheel /suspension even moves. It's this initial load that leads to damage from potholes if the wheel can't handle it, no lightweight wheel will save you if the impact load hits the lip before the wheel can even travel.



JWL & SAE175/1981 Impact Test literally does not care about the weight of the wheel, only the load rating or what the wheel is going to hold up.

A slow motion video easily explains this as well, the tire is crushed and the curb impacts the wheel before it even takes into account suspension travel. The wheel is the first thing to absorb impact energy in the event of a pothole before it's transmitted upward.

Lighter is not always better when it comes to potholes; it really comes down to how the structure is designed and the load rating, for instance my personal set I included extra material around the edges and a groove to essentially form an I beam channel to make the forward lip very stiff, creating a large section modulus for shear and bending stresses. The wheel is 3lbs heavier compared to a comparable set, but it is way more pothole safe.

 

[Volfy]

You're overthinking and the example you gave is more for harmonic motion of shock/spring systems over uneven pavement (not a pothole) for ride quality (slow speed dampening).

Potholes are more of an instantaneous point load. Therefore you need to consider that the wheel doesn't move during initial contact as the tire gets crushed. Impact loading and physics are an entirely different beast since you have to assume zero movement in a small time space. You're also forgetting that the wheel doesn't magically transmit the energy through it's structure, the load is absorbed through the flange and barrel face and then through the spokes and central hub before the wheel /suspension even moves. It's this initial load that leads to damage from potholes if the wheel can't handle it, no lightweight wheel will save you if the impact load hits the lip before the wheel can even travel.

Overthinking?! Absolutely not. A pothole is nothing more than a large undulation with a rapid slew rate. The response of the suspension works no differently than any other undulation with varying magnitude. If you are suspension engineer, that is exactly how you would look at it.

You are talking about how the wheel can survive a direct impact - road on wheel lip. Of course you would. As a wheel designer, that falls on your to manage the worse case scenario.

I as a car owner, OTOH, am not looking for potholes to hit, in order to find out how much damage my wheels would sustain in a direct hit. I'd rather avoid that in the first place - as would any car owner. To do this requires a holistic approach, one that examines how to optimize the suspension setup in its totality, instead of a myopic focus purely on wheel strength and impact survivability (as a wheel designer would... and rightfully should).

Now, as car owners, we cannot redesign the suspension entirely, but there are a few things we can do:

1. Reducing Mus (unsprung mass). I've already covered this in post #25 above. All things being equal, a substantially lighter wheel will allow the suspension to response faster to road undulations - large or small.

2. Increase kt (tire as an air spring). The pneumatic tire acts like an air spring to cushion the wheel from a direct hit. It acts just like the air suspensions you find in some cars and the aftermarket airbags some folks install. You can vary/tune the spring constant (via psi pressure) and suspension travel (different sidewall height).

This is where I take issue with mfr for spec'ing 19" wheels and those who would recommend 19" for aftermarket.

Ideally, the wheel diameter should be no larger than what is required to fit over the brakes (sized appropriately for the car's performance and anticipated duty severity). 18" wheels clear the stock Brembos with room to spare. Kia went with 19" purely for cosmetic reasons, because most folks are drawn to the racy look of big wheel look with low-profile tires, so the mfr caters to that.

Look at the Cadillac CT4 Blackwing. GM was able to squeeze 6-piston Brembo calipers over 15" front rotors under stock 18" wheels. They actually went to great lengths to work with Brembo to customize their calipers to make it happen. Why GM insisted on 18"? They could've copped out and go 19". They did it because they resisted bowing to consumers' vanity demand and actually listened to their engineers on what works best. By staying with 18" wheel/tire, they minimizes unsprung weight, reduced rotational and linear inertia. They did exactly what I've outlined above. All without compromising performance or street survivability.

Contrast this with the Stinger. It uses 4-pot Brembos over 13.8" rotors. 18"s fit easily. I've got 4 sets of 18"s between G70 and Stinger. Heck, 17" might even fit, if Kia really tried. Yet... they spec'ed 19". Doing so created more unnecessary problems. My G70 came with 19x8 and 19x8.5 that weight 34 lbs front and 34.5 lbs rear. Awfully heavy pigs, made necessary because the low-profile 19" tires required these wheels to be toughed up for direct impact survivability (just like you do with your own wheels). More unsprung mass means more inertia for the rest of the suspension components to deal with. It's a cascading effect with compounding negative consequences. All for the sake of vanity.

So, when I, as an owner, select an aftermarket wheel, why on earth would I want to stay with 19"?! Or even go to 20"?! Not for performance. Not for street survivability. Absolutely no reason other than for looks. Or "personal preference" as you stated. Not my place to tell others how they should spend their disposable income. You buy what you like and live with your choices, and consequences.

However, to argue on technical grounds that somehow a heavier 19" wheel is a superior choice for the Stinger?! Given the brake caliper/rotor sizes?! That somehow lighter 18" wheels wouldn't be better, all things being equal?! Bring some better engineering argument.

JWL & SAE175/1981 Impact Test literally does not care about the weight of the wheel, only the load rating or what the wheel is going to hold up.

If it's an impact test, why would they care about weight? When you submit your wheel for impact testing, the weight is as you delivered. The wheel either meets the test criteria for the load rating, or it does not. It's not the testing agency's job to critique on the relative merits or demerits of your design. They couldn't care less. If it fails, it is your job to go back to your Solidworks and figure out how to improve it.

It is disingenuous to imply that because the impact test doesn't care about how heavy your wheels are, somehow that must mean light weight doesn't matter.



As for the rest of you post #28 above, you've simply argued against the use of low-profile tires. This further adds to the advantages of a lighter 18" wheel, with which you can spec a higher profile tire, to avoid the pitfalls exemplified with your video entitled "Low-Profile Tires vs. Potholes."

 

[Snicklefritz]

Kia went with 19" purely for cosmetic reasons, because most folks are drawn to the racy look of big wheel look with low-profile tires, so the mfr caters to that.

lol. generations of hot wheels kids who 'grew up' into car enthusiasts. hot wheels are directly responsible for the 'rubber band' tires aka high aspect ratio tires so popular the world over. I used to hate the look across the board. but now I think it looks cool on the right kind of vehicle. rubber band tires and monster wheels look absolutely daft on any pickup or genuine off-road vehicle. and the extreme rubber band tires still look ridiculous on any car. the other look that I find stupid is the puny narrow tires look on lowered cars, favored for some cultural reason by our brothers and sisters to the south.

 

[Volfy]

lol. generations of hot wheels kids who 'grew up' into car enthusiasts. hot wheels are directly responsible for the 'rubber band' tires aka high aspect ratio tires so popular the world over. I used to hate the look across the board. but now I think it looks cool on the right kind of vehicle. rubber band tires and monster wheels look absolutely daft on any pickup or genuine off-road vehicle. and the extreme rubber band tires still look ridiculous on any car. the other look that I find stupid is the puny narrow tires look on lowered cars, favored for some cultural reason by our brothers and sisters to the south.

lol. so true. I'm not categorically against low profile tires. They have their place in the automotive world, given the right applications. In fact, for the next set of 200 tread wear tires on my track wheels, I'm going from the current 245/40R18 to a lower-profile 255/35R18. Doing so would reduce tire squirm at high lateral loads (high cornering G-forces) near the limits. The reduced rolling diameter would quicken acceleration, particularly in lower gears. My speedometer would be off, but for track use only... who cares.

However, that's for track day and AutoX applications. While not every track I've been on are always 100% billiard table smooth, they are generally far better than what we encounter on public roads. Certainly no big potholes ready to bust my wheels. For everyday commuting and street driving, tire considerations have different priorities than track. Besides, I'm not into street-heroics and petty pissing contest. While I do enjoy spirited driving in the twisties, having fun at sane speeds over public roads does not require rubber band tires.

But... folks see race cars tearing up tracks on super low-file tires and naturally associate that with high-performance. So when it comes time to pimp up their street rides, they want to replicate that same racy "aggressive" look. Scraped lips and bent rims be damned.

 

[Snicklefritz]

it seems that close to a hundred percent of visual mods are for 'the look' and any performance gains are purely subjective or often the reverse which means the owners are in denial. but their cars do look 'cool.'

 

[Submarines]

Overthinking?! Absolutely not. A pothole is nothing more than a large undulation with a rapid slew rate. The response of the suspension works no differently than any other undulation with varying magnitude. If you are suspension engineer, that is exactly how you would look at it.

You are talking about how the wheel can survive a direct impact - road on wheel lip. Of course you would. As a wheel designer, that falls on your to manage the worse case scenario.

I as a car owner, OTOH, am not looking for potholes to hit, in order to find out how much damage my wheels would sustain in a direct hit. I'd rather avoid that in the first place - as would any car owner. To do this requires a holistic approach, one that examines how to optimize the suspension setup in its totality, instead of a myopic focus purely on wheel strength and impact survivability (as a wheel designer would... and rightfully should).

Now, as car owners, we cannot redesign the suspension entirely, but there are a few things we can do:

1. Reducing Mus (unsprung mass). I've already covered this in post #25 above. All things being equal, a substantially lighter wheel will allow the suspension to response faster to road undulations - large or small.

2. Increase kt (tire as an air spring). The pneumatic tire acts like an air spring to cushion the wheel from a direct hit. It acts just like the air suspensions you find in some cars and the aftermarket airbags some folks install. You can vary/tune the spring constant (via psi pressure) and suspension travel (different sidewall height).

This is where I take issue with mfr for spec'ing 19" wheels and those who would recommend 19" for aftermarket.

Ideally, the wheel diameter should be no larger than what is required to fit over the brakes (sized appropriately for the car's performance and anticipated duty severity). 18" wheels clear the stock Brembos with room to spare. Kia went with 19" purely for cosmetic reasons, because most folks are drawn to the racy look of big wheel look with low-profile tires, so the mfr caters to that.

Look at the Cadillac CT4 Blackwing. GM was able to squeeze 6-piston Brembo calipers over 15" front rotors under stock 18" wheels. They actually went to great lengths to work with Brembo to customize their calipers to make it happen. Why GM insisted on 18"? They could've copped out and go 19". They did it because they resisted bowing to consumers' vanity demand and actually listened to their engineers on what works best. By staying with 18" wheel/tire, they minimizes unsprung weight, reduced rotational and linear inertia. They did exactly what I've outlined above. All without compromising performance or street survivability.

Contrast this with the Stinger. It uses 4-pot Brembos over 13.8" rotors. 18"s fit easily. I've got 4 sets of 18"s between G70 and Stinger. Heck, 17" might even fit, if Kia really tried. Yet... they spec'ed 19". Doing so created more unnecessary problems. My G70 came with 19x8 and 19x8.5 that weight 34 lbs front and 34.5 lbs rear. Awfully heavy pigs, made necessary because the low-profile 19" tires required these wheels to be toughed up for direct impact survivability (just like you do with your own wheels). More unsprung mass means more inertia for the rest of the suspension components to deal with. It's a cascading effect with compounding negative consequences. All for the sake of vanity.

So, when I, as an owner, select an aftermarket wheel, why on earth would I want to stay with 19"?! Or even go to 20"?! Not for performance. Not for street survivability. Absolutely no reason other than for looks. Or "personal preference" as you stated. Not my place to tell others how they should spend their disposable income. You buy what you like and live with your choices, and consequences.

However, to argue on technical grounds that somehow a heavier 19" wheel is a superior choice for the Stinger?! Given the brake caliper/rotor sizes?! That somehow lighter 18" wheels wouldn't be better, all things being equal?! Bring some better engineering argument.


If it's an impact test, why would they care about weight? When you submit your wheel for impact testing, the weight is as you delivered. The wheel either meets the test criteria for the load rating, or it does not. It's not the testing agency's job to critique on the relative merits or demerits of your design. They couldn't care less. If it fails, it is your job to go back to your Solidworks and figure out how to improve it.

It is disingenuous to imply that because the impact test doesn't care about how heavy your wheels are, somehow that must mean light weight doesn't matter.



As for the rest of you post #28 above, you've simply argued against the use of low-profile tires. This further adds to the advantages of a lighter 18" wheel, with which you can spec a higher profile tire, to avoid the pitfalls exemplified with your video entitled "Low-Profile Tires vs. Potholes."

Yes overthinking.

A pothole is a concentrated point load with high impact stress before its distributed across various surfaces, you can not treat it like any normal bump with smooth-ish entry/exit. If the tire fully compresses and cannot absorb the force; then the load is transfered instantaneously to the wheel's structure at a point load and you treat it as a static load event (wheel doesn't move). Generally this is the case with any pothole big enough to cause wheel damage.

At this point Mus (your wheel) doesn't really matter because it needs to absorb the impact load and redistribute it before moving and transferring it to the springs and then movement occurs. If you look at an image of any bent wheel, it's bent at a single point which means the wheel has to absorb the energy before the suspension reacts.

A shorter side wall does have the benefit of faster response times for handling because of the stiffer side wall, which is probably why Kia went with 19's, taking from Albert Biermann's BMW experience. Kia does offer the stinger with 18's, my GT1 came with 18's and all seasons; 17" will not fit and will probably lead to a very squishy ride which defeats the purpose of the car.

Also I would appreciate it if you didn't put words in my mouth. I never stated that 19" wheels are superior to 18"'s. I simply stated that lighter wheels are not always better since chasing weight savings usually leads to compromises in strength (post #21). You can choose whatever diameter makes you happy but saying one is superior for potholes simply on assumption that it's lighter is brash. It really depends on the structure of the wheel/lip and the barrel thickness, a flow form wheel has a thinner barrel to reduce weight because of the forming process allows it to, but in exchange for weight reduction, the barrel cross sectional area is reduced and therefore weaker against shear stress.

Carbon fiber and magnesium wheels are 30% lighter than cast alloy, but they are notorious for shattering at a pothole. The enkei RPF01 is one of the lightest cast wheels in existence but they easily get bent from potholes because the front lip is unsupported by any spokes thus less stiff cross section. My previous set of enkei TS10 18x8.5 on 225/40/18 tires bent within a winter season from a relatively low speed pothole, theoretically they should have been the best to survive from your statements.

I'm addressing solely pothole survivability, for handling purposes the lightest wheel possible in combination with a stiffer side wall and wider tires is best.

 

[Volfy]

Yes overthinking.

A pothole is a concentrated point load with high impact stress before its distributed across various surfaces, you can not treat it like any normal bump with smooth-ish entry/exit. If the tire fully compresses and cannot absorb the force; then the load is transfered instantaneously to the wheel's structure at a point load and you treat it as a static load event (wheel doesn't move). Generally this is the case with any pothole big enough to cause wheel damage.

At this point Mus (your wheel) doesn't really matter because it needs to absorb the impact load and redistribute it before moving and transferring it to the springs and then movement occurs. If you look at an image of any bent wheel, it's bent at a single point which means the wheel has to absorb the energy before the suspension reacts.

A shorter side wall does have the benefit of faster response times for handling because of the stiffer side wall, which is probably why Kia went with 19's, taking from Albert Biermann's BMW experience. Kia does offer the stinger with 18's, my GT1 came with 18's and all seasons; 17" will not fit and will probably lead to a very squishy ride which defeats the purpose of the car.

Also I would appreciate it if you didn't put words in my mouth. I never stated that 19" wheels are superior to 18"'s. I simply stated that lighter wheels are not always better since chasing weight savings usually leads to compromises in strength (post #21). You can choose whatever diameter makes you happy but saying one is superior for potholes simply on assumption that it's lighter is brash. It really depends on the structure of the wheel/lip and the barrel thickness, a flow form wheel has a thinner barrel to reduce weight because of the forming process allows it to, but in exchange for weight reduction, the barrel cross sectional area is reduced and therefore weaker against shear stress.

Carbon fiber and magnesium wheels are 30% lighter than cast alloy, but they are notorious for shattering at a pothole. The enkei RPF01 is one of the lightest cast wheels in existence but they easily get bent from potholes because the front lip is unsupported by any spokes thus less stiff cross section. My previous set of enkei TS10 18x8.5 on 225/40/18 tires bent within a winter season from a relatively low speed pothole, theoretically they should have been the best to survive from your statements.

I'm addressing solely pothole survivability, for handling purposes the lightest wheel possible in combination with a stiffer side wall and wider tires is best.

Sorry to hear you have bent so many wheels. I can understand now why, in your own wheel designs, you tend to obsess over reinforcing them to guard against impact damage, even if it means adding lbs of weight.

But... have you ever stopped to reconsidering that maybe there is a reason why you have bent so many wheels? Perhaps you could've approached wheel and tire sizing differently to change those outcomes? Maybe, just maybe, you were, uh... ever so slightly, um... incorrect in your assumptions?

I myself can say, in all honesty, that I have not bent a single wheel in close to 40 yrs of driving. This despite having lived in many states - and driven in several other countries - including over some pretty questionable pavement. Maybe, just maybe, what I wrote in this thread are all wrong, and I've just carried a lucky streak for all these years. Then again... maybe not.


BTW, I don't put any words in anybody's mouth, any more than I wish others to put words in mine. You yourself recommended two set of wheel and tires sizes for the Stinger. Both 19". One would reason that if you did believe 18's were better, that you would offer them instead of the 19's. Otherwise, that would be the very definition of disingenuity - telling others to believe something you yourself don't believe in. I would hope you are better than that.

So... you think Herr Biermann spec'ed Stinger's 19" wheels over 13.8" brake rotors, huh? Und für best performance, ja? Aber natürlich! Herr Albert Biermann von Bey Em Vey. The very same BMW that spec'ed 18" wheels over 15" front brake rotors for the M3? That BMW?! Well, that seems to agree with the earlier example I mentioned - CT4-V Blackwing, which also spec'ed 18" wheels over 15" rotors. Same engineering paradigm of sizing wheels just large enough to fit over the brakes. To minimize unsrpung weight and reduce rotational and linear inertia. Hmmm...

So either Herr Biermann's tuning philosophy changed completely when he landed in Korea. Or... maybe there are some other - less performance centric - considerations at play, ja?


I don't ever believe I'm above reproach. Given sound reasoning, I'm always willing to learn. Unfortunately, I don't see that here.

 

[Aarvix]

All four of my 20s are flow "forged" and bent.

I'm replacing them with.......more 20s.

I like they way they look, gotta pay to play.

 

[JSolo]

Treat the street like a slalom course, avoid the potholes using full width of your lane (and adjacent if not occupied). That's what I do here. Even slow down for rail road tracks.

 

[Snicklefritz]

monster pot holes appear long before winter is over and out. I do the same, bob and weave to avoid the crap, this includes goopy patches when my car is clean, good practice for watching out for the pot holes actually, it all keeps your attention focused on the road.

Treat the street like a slalom course, avoid the potholes using full width of your lane (and adjacent if not occupied). That's what I do here. Even slow down for rail road tracks.

 

[JSolo]

^^I've been pretty successful for the most part, occasionally one will catch me. I do try to keep a good following distance at all times. Gives more time to react without freaking out other cars around me.

 

[Volfy]

I absolutely agree. Nothing wrong with just taking it easy on public roads. Slowing down buys you time; Time buys you options; options give you ways to avoid road hazards. Or, at the very least, minimize the impact.

This is far better than the fatalistic approach that assumes there is nothing you can do about pothole hard hits. Then take the pessimistic measure of buying extra-tough wheels and paying the price of heavier unsprung mass - along all the suspension ills that come with that.

 

[Volfy]

BTW, @JSolo , those of us who are seasoned riders (especially sport touring types) tend to adopt the approach of actively assuming everyone - including the road - is out to kill us. On 2 wheels, we are constantly on the alert looking for hazards. As soon as we avoid one, we are right back on the look out for the next hazard(s). No sense arguing with other motorists when you're on 2 wheels, because you will lose. Better to avoid and get da heck away.

Some call it defensive driving... or Zen of riding. A car is nowhere near as agile as a bike, but carrying that same mentality into my driving has served me well.