Bent Rim…stronger and lighter rims? I need advice

[Brichinelo]

Exactly the ones i have. Price/pound ratio is awsome and look great on stinger.

You got any pics of your wheel setup and what size rims ?

 

[JSolo]

^^True... In 20 years of riding I went down twice. Once my own doing early on, second time rear ended stopped at a light. Yes, assume you're invisible and everyone is out to get you. Always on the lookout for escape paths. I don't ride any more, but this strategy has carried over into my driving.

<<<--- FZ1 with luggage and gps - poor man's sport tourer.

 

[Brichinelo]

But Those stiff sidewall comes with penalties:

1. Weight. again rears its ugly head. There is just no way around this. More load handling out of less sidewall height means more materials and reinforcements. Look up any of the more popular performance tires and you'll see this for yourself. All else being equal, lower profile (less sidewall) will invariably carry a lower load rating, meaning their cannot sustain the same load as a higher profile tire of the same series/dia/width. And... when you do find another tire that does have an equivalent load rating as the higher profile tire, it will be heavier.

2. Reduce tire compliance. A 20" tire on a Stinger will have to be ultra low profile in order to maintain the same rolling diameter as an 18" tire. This means 255/30R20 vs. 255/40R18. When a tire has that little sidewall - and having to be ultra stiff to carry the same load rating - it simply will not flex at all. While this might not be a big deal on a billiard table smooth race track, most of us drive on roads that are far less forgiving. Over rough pavement and over larger undulations, a tire needs a certain amount of compliance in order to stay adhered to the road surface and to maintain grip. Too stiff a sidewall and too little compliance will simply make the tire bound off the pavement and lose contact/grip. The best tire compound in the world ain't gonna do you much good when it is in the air.

Also, some compliance is necessary for optimum accel and braking. Most folks familiar with drag racing know this.

3. NVH (Noise, Vibration, and Harshness). Short stiff sidewalls will transmit more NVH (Noise, Vibration, and Harshness) up the wheel, thru the suspension and into the cabin. That means more road noise. That also means your suspension will be more stressed and have to work harder to dampen the additional movement that would have been otherwise absorbed by a more compliant tire.

4. Road hazards. This brings us inexorably back to the topic of this thread. There is no escaping the fact that your 20" rim - with a 255/30R20 tire - is sitting some 2" off the pavement. Now imagine that wheel/tire hitting a pothole. Even at modest speed of say 60mph, that awfully small "crumple zone" will have a tough time absorbing that impact, before the suspension has a chance to react. Little surprise that Stinger/G70 forums and FB pages are constantly littered with folks posting their dented/crack rims.

I bent my 20 inch black rim a while back and had to get it professionally repaired. I asked this question a while back about to how to combat potholes and messed up roads and really didn’t get a clear consensus. I just sold my oem 18 inch setup so I’m left with my 20s. If I did want to do 19s all the way around (square ) what would be the best tire setup. Currently sitting at 245/35/20. And I love the info and knowledge on this thread. Keep it going

 

[Ohiocruiser]

You got any pics of your wheel setup and what size rims ?

245/40-18 with 8.5 wide wheels.

 

[Brichinelo]

245/40-18 with 8.5 wide wheels.View attachment 78084

Looking good . Highly considering this setup after reading this thread. Square ? And now lowered or anything right ?

 

[Volfy]

<<<--- FZ1 with luggage and gps - poor man's sport tourer.

I had an '07 FZ1, set up for a Monokey top case and Givi V35 panniers. Excellent sport tourer.

I still ride, year round. Ninja 1000 and K1600GT. Commute in every chance I get, though lately has not been too often. I get too lazy, cus the Stinger is just so darn comfy.

 

[Volfy]

245/40-18 with 8.5 wide wheels.View attachment 78084

Out of the available colors for TFR, bright silver is a great match with that blue.

 

[JSolo]

^^Almost bought a K1600GT in '19. Steal of a deal, 2014 model, <5K miles, $15K OTD, from a harley dealership. The stars were not in alignment and I had to back out of the deal. That thing was a rocket. Very sensitive throttle. Hid its weight well.

These days I still have the M class but don't see riding in this area any time soon. Too dangerous. Too old to recover quickly.

 

[Ohiocruiser]

Looking good . Highly considering this setup after reading this thread. Square ? And now lowered or anything right ?

Correct, square setup. And it's on ark gt-f springs. But with my weight reduction "mods", i think, i will need more aggressive springs, to bring it down again.

 

[Ohiocruiser]

Out of the available colors for TFR, bright silver is a great match with that blue.

I wish they were little brighter. They are light grey, forgot the name for that color.

 

[Volfy]

I bought my '14 w/ less than 5k miles for $13.5k from a police officer in Okla. City, back in 2018. I've had many sport tourers over the years. None had the turbine smooth power of this inline6.

A lot of guys get into pissing contest with their cars. I never bother, precisely because it's all rather pointless to me. Every one of the last ~15 bikes I've had would out-accelerate anything on 4wheels with a simple twist of the wrist. Not that I ever bother with those sort of silly street contest. Stuff like that is better reserved for the track - be it 2 or 4 wheels.

 

[Volfy]

FYI, this is mine with the TFR, at Motorsport Ranch Cresson. 245/40R18 Ecsta V730 track tires. Eibach Pro kit springs.

 

[Volfy]

I wish they were little brighter. They are light grey, forgot the name for that color.

Storm Gray, I think. Mine is called just "Copper". I almost went with the Gun Metal, which my son originally preferred. But after looking at tons of different online pics - at different angles - of all 3 colors on similar red color cars, we went with the Copper.

 

[Brichinelo]

Correct, square setup. And it's on ark gt-f springs. But with my weight reduction "mods", i think, i will need more aggressive springs, to bring it down again.

I personally love the square look. Looking nice. No problem with the springs even on 18s ? Would springs be better on 18s ?

 

[Redleg94]

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.

The only time I've ever hit potholes hard is when I simply couldn't see them, such as when the hole is filled with water and it is both dark and raining. No contrast with the rest of the road at all.

 

[Volfy]

I personally love the square look. Looking nice. No problem with the springs even on 18s ? Would springs be better on 18s ?

With the stock wheels, especially the heavy 19"s (which could weight as much as 35 lbs each), the stock suspension is rather soft. This is an artifact of having so little tire compliance with the very low profile stock 19" tires, that Kia had to soften the shock and spring in order to get sufficiently smooth ride quality. With a heavy wheel and soft springs and shock, the system is underdamped. This means the articulation of the unsprung mass tend to oscillate after a perturbation (such as hitting a bump in the road), like the blue line in the below graph, albeit exaggerated.

So, now you install a set of wheels that are 15 lbs lighter vs. the stock 19s. That is 42% lighter wheel, or 25% lighter wheel/tire assembly. Less mass for the same spring and shock to control means the system is able to suppress the perturbation quicker... to perhaps the red line.

Even without changing the shocks, reducing unsprung mass means the shocks have that much less inertial energy to absorb with each articulation. You have, in effect, better matched the wheel weight to an otherwise underdamped shock.

Now, you install lowering springs that are 15% stiffer, which means for every inch of suspension travel, the spring exerts 15% more force to counter that suspension movement. This can improve the perturbation response down to the orange line.

In reality, the changes are not as drastic. This graph is just an example damping graph I pulled off of Google for illustration purposes only. That said, both reducing unsprung weight and increasing the spring rate will most definitely improve suspension control in the Stinger's case.

The rest of the suspension doesn't know what diameter wheel you have on. All they feel is the unsprung mass that they have to control. The lighter that mass is, the more effective they are able to control the movement, the quicker they are able to re-establish stability. Again, all else being equal, lighter is always better.

Google "damped mass spring system", and you can read more about these very fundamental principles that every engineering student has to learn.

 

[Brichinelo]

With the stock wheels, especially the heavy 19"s (which could weight as much as 35 lbs each), the stock suspension is rather soft. This is an artifact of having so little tire compliance with the very low profile stock 19" tires, that Kia had to soften the shock and spring in order to get sufficiently smooth ride quality. With a heavy wheel and soft springs and shock, the system is underdamped. This means the articulation of the unsprung mass tend to oscillate after a perturbation (such as hitting a bump in the road), like the blue line in the below graph, albeit exaggerated.

So, now you install a set of tires that are 15 lbs lighter vs. the stock 19s. That is 42% lighter wheel, or 25% lighter wheel/tire assembly. Less mass for the same spring and shock to control means the system is able to suppress the perturbation quicker... to perhaps the red line.

Even without changing the shocks, reducing unsprung mass means the shocks have that much less inertial energy to absorb with each articulation. You have, in effect, better matched the wheel weight to an otherwise underdamped shock.

Now, you install lowering springs that are 15% stiffer, which means for every inch of suspension travel, the spring exerts 15% more force to counter that suspension movement. This can improve the perturbation response down to the orange line.

In reality, the changes are not as drastic. This graph is just an example damping graph I pulled off of Google for illustration purposes only. That said, both reducing unsprung weight and increasing the spring rate will most definitely improve suspension control in the Stinger's case.

The rest of the suspension doesn't know what diameter wheel you have on. All they feel is the unsprung mass that they have to control. The lighter that mass is, the more effective they are able to control the movement, the quicker they are able to re-establish stability. Again, all else being equal, lighter is always better.

Google "damped mass spring system", and you can read more about these very fundamental principles that every engineering student has to learn.

Thanks for the school lesson my guy. Very much appreciated. To Google I go.

 

[SRV]

Interesting replies for sure.

My take is simple, buy the wheels that you think look best, and stay on roads you're familiar with, avoid the ones you know are rough, and be vigilant on unfamiliar ones.

Back in 2002, I started looking for wheels/tires for my '87 928 5-speed. The stock rims were 16" and to me, the wheel wells looked cavernous with those small rims.

So I wanted to get 18's to fill out the wheel wells, and everyone told me I will bend the 18's and should instead get a set of 17's.

Everybody also said I should get 5-spokes because of this and that, but I didn't care for 5-spokes, plus literally everyone had them on their 928's.

So I went online looking, and looking some more for a wheel I really liked. And one night I finally came across the 'mesh' style wheel and knew that was the style for me.

Next I narrowed my search to looking only at the mesh wheels, and fell in love with 18" 3-piece HRE 540R's. The only problem, they cost $5000+ even back then.

I bit the bullet, and ordered 265x35 and 295x30 tires for them - from last summer and now 20+ years old:



It turned out to be be money well-spent and never regretted it. To this day I get compliments on the car and its wheels, and I've never dented nor bent them despite driving it hard on the back roads of Wisconsin with my buddies.

To reiterate, buy the wheels you really like, and do your best to be careful on non-familiar roads, and you'll never regret your purchase and feel really good every time you look at the car.

18" Cargraphics on my '96 6-speed 993:



19" HRE's:



No bent wheels even with the rough Wisconsin roads.