Negative effects of stretched tires?

[jonjon0nline]

I am looking to get the Euro look with low offset wheels and stretched tires. I would like to know the ill effects of doing so. Any one have any info? TIA.

[SILV3R]

bump. would like to know too.

haha you want the euro look too huh? i'm interested on getting rondell 58's (17x10, offset:15mm).

[LuvMy328is]

Check out my sig. You can get the ADR M classic in an 18x8.5 et40 and get a 225/40/18 on Comfortably or go 245/35/18 and add some camber to the rear and reduce rubbing to a minimum. And its MUCH Cheaper lol
~Phil

[SILV3R]

i have 18x8.5 with 225/40.
245/35 tires might be an option if i decide to keep my wheels.

[Ausbimmer]

Staggered tyres will produce understear, also a larger diametre and width rim will be heavier then it needs to be. I can't see any positive handling effects from it. Sure looks good though.

[jonjon0nline]

Hmm.. Maybe it wasn't clear. I plan on stretching 215s to fit 8" wide wheels, thus giving it the stretched Euro look. Only reason I ask is because I do a lot of sprited driving in the hills and intend to do some auto-x.

[jonjon0nline]

Originally Posted by SILV3R

bump. would like to know too.

haha you want the euro look too huh? i'm interested on getting rondell 58's (17x10, offset:15mm).

I don't see this happening with stock fenders. Not even a roll could make it work. You would either have to pull/roll your fenders and run some crazy neg camber or get some flares.

[SILV3R]

found this dude's car on bmw-sydikat. this is what i wish my car will have one day...
http://www.bmw-syndikat.de/bmwsyndik..._Title=BMW+E36
17x10 with 245/35/17 rubber according to him. wonder what he did to make it work?

[ozbmw]

Positive effects of tyre stretching:
Nil

Negative effects:
Rims left totally exposed to kerb rash damage
Tyres distorted due to being fitted to too wide a rim requiring much higher inflation pressures to prevent excessive wear on the edges of the tread surface
Rough choppy ride due to higher inflation requirements
Likelyhood of actually having the tyre coming off the bead if impacted
Higher wear rate on suspension components
Higher wear rate on wheel bearings
Poor directional stability due to wrong offset being used

You do the maths.......the best handling car built in the 90s will no longer feel that great to drive


I'll stick with 235/40ZR17 on +41mm offset Forged Motorsports

[SILV3R]

Originally Posted by ozbmw

Positive effects of tyre stretching:
Nil

Negative effects:
Rims left totally exposed to kerb rash damage
Tyres distorted due to being fitted to too wide a rim requiring much higher inflation pressures to prevent excessive wear on the edges of the tread surface
Rough choppy ride due to higher inflation requirements
Likelyhood of actually having the tyre coming off the bead if impacted
Higher wear rate on suspension components
Higher wear rate on wheel bearings
Poor directional stability due to wrong offset being used

You do the maths.......the best handling car built in the 90s will no longer feel that great to drive


I'll stick with 235/40ZR17 on +41mm offset Forged Motorsports

thanks for the info. now you got me thinking twice about sportin the euro look. ehh..nonetheless it still looks f'n sick!

[Don Nguyen]

Doesn't stretching tires actually make what would be a soft sidewall have a somewhat stiffer sidewall effect?

[Digital Jedi Rx]

Not sure where the conecpt orginated from. I thought it was Japan, but could obviously be wrong.

From a drifting perspective it is call hipari. There are a couple of reason why it is done. One being that it gives you a VERY stiff sidewall, so in effect you can have an inexpensive low profile tire perform more like a very expensive low profile tire. The other reason being is that when go go through tires frequently, you just sometimes got to run with what you got, at sometimes this means not having the "optimal" size, hence the concept of hipari (meaning stretched tire).

I know drifters will argure up and down that this is the best thing in the world. MAYBE for drifting it is, but I would not call this optimal for any type of track or auto-x racing.

[Patrón]

Originally Posted by ozbmw

Positive effects of tyre stretching:
Nil

Negative effects:
Rims left totally exposed to kerb rash damage
Tyres distorted due to being fitted to too wide a rim requiring much higher inflation pressures to prevent excessive wear on the edges of the tread surface
Rough choppy ride due to higher inflation requirements
Likelyhood of actually having the tyre coming off the bead if impacted
Higher wear rate on suspension components
Higher wear rate on wheel bearings
Poor directional stability due to wrong offset being used

You do the maths.......the best handling car built in the 90s will no longer feel that great to drive

I'll stick with 235/40ZR17 on +41mm offset Forged Motorsports

QFP

[EricP]

My car had ugly, heavy, huge chrome wheels with stretched tires on it (more so in the rear than front) when I got it. I don't know how many times I curbed those pieces of crap, good riddens. I made sure to get enough tire to at least somewhat protect my wheels when I replaced them.

[SILV3R]

i don't consider curbing wheel as a negative effect as long as you are careful.

the real concern is the performance/long term effects side of it. ozbmw pretty much cleared things up.

[egk2]

Originally Posted by ozbmw

Positive effects of tyre stretching:
Nil

Negative effects:
Rims left totally exposed to kerb rash damage
Tyres distorted due to being fitted to too wide a rim requiring much higher inflation pressures to prevent excessive wear on the edges of the tread surface
Rough choppy ride due to higher inflation requirements
Likelyhood of actually having the tyre coming off the bead if impacted
Higher wear rate on suspension components
Higher wear rate on wheel bearings
Poor directional stability due to wrong offset being used

You do the maths.......the best handling car built in the 90s will no longer feel that great to drive

I'll stick with 235/40ZR17 on +41mm offset Forged Motorsports

Can I ask where you got your information from?
The only thing I agee with is that the wheels are more prone to curb damage but on the same note if you brushed up against a curb with 245's on a 9" wheel I bet your wheel will be curbed as well.
I have stretched tires, I run manufacturers recommended tire pressure and have wear on the insides of the tires from neg camber NOT from having stretched tires, ride is not choppy, I drive the car daily with NO ill effects, many many people run stretched tires and I have yet to see a tire pop off the bead. Higher wear rate on suspension? Highly doubtful. Directional stability is fine as well. Do you have first hand experience in regards to stretched tires? Just curious.

[ozbmw]

Yes, I have over 1,500,000 kilometres driving experience in mostly modified cars including these type setups and have spoken to several owners who have tried it and then returned to normal setups. Read the initial post again, the original poster was not just asking about tyre stretching but also running low offset wheels. The engineers at BMW didn't just make the offset up, they tried several setups before deciding that E36 for instance should run with offsets in the 40 pos. range. This has a lot more to do with steering, handling, wheel bearing design not just trying to fit a tyre inside the wheel arches, running lower offsets causes more wear to bearings as the load is moved further out. Tyre companies also design their tyres around a specific rim width for each tyre width for a reason, one of those reasons is to give it the maximum safety margin to stay on the bead of the rim. Yes its true that stretching results in apparently stiffer sidewall, but that does not equate to better handling and will transfer more of the movement to the suspension components >more wear. Some of these changes will not be immediately apparent others will be noticed. Changing the track width of a setup will have an effect on directional stability. As I said this is mostly from personal experience, and your knowledge and experience may far exceed mine but it has got us thinking again. Cheers, Matt

[SQ Bimmer]

I think it looks pretty stupid, especially that car with the 17x10s. It looks like something I would see in South Central LA on a pickup truck.

[egk2]

Originally Posted by ozbmw

Yes, I have over 1,500,000 kilometres driving experience in mostly modified cars including these type setups and have spoken to several owners who have tried it and then returned to normal setups. Read the initial post again, the original poster was not just asking about tyre stretching but also running low offset wheels. The engineers at BMW didn't just make the offset up, they tried several setups before deciding that E36 for instance should run with offsets in the 40 pos. range. This has a lot more to do with steering, handling, wheel bearing design not just trying to fit a tyre inside the wheel arches, running lower offsets causes more wear to bearings as the load is moved further out. Tyre companies also design their tyres around a specific rim width for each tyre width for a reason, one of those reasons is to give it the maximum safety margin to stay on the bead of the rim. Yes its true that stretching results in apparently stiffer sidewall, but that does not equate to better handling and will transfer more of the movement to the suspension components >more wear. Some of these changes will not be immediately apparent others will be noticed. Changing the track width of a setup will have an effect on directional stability. As I said this is mostly from personal experience, and your knowledge and experience may far exceed mine but it has got us thinking again. Cheers, Matt

You make some valid points but there is no hard evidence or any extensive testing to back up your statements.

[ozbmw]

I have found that on these forums you seek and receive opinions usually based on experience. I doubt that anyone is ever going to spend any time trying to prove the benefits or otherwise of stretching undersize tyres on oversize rims. In all honesty the only possible reason I can see for doing it is to have the widest possible rims under their car for aesthetic reasons alone. If you like the look of them (I don't) then go for it. However there is no doubt that based on pure physics alone it is not the best practice. When tyres are made the maker recommends a rim width to ensure the overall shape of the tire on the rim allows the rubber to do its job, ie. to provide grip. Changes to that shape caused by changes in rim width will usually have a negative effect on grip. Secondly, fitting a rim wider than required by the particular tyre will add 'unsprung weight' to the car, that again is known to be a big no-no, that is why race cars use magnesium alloys to get the lightest wheel for a given strength and size requirement. As we all know it takes more force to overcome the inertia of a heavy wheel than a light one, therefore all things being equal a car will accelerate faster with a lighter wheel. Narrower wheel is lighter than an excessively wide one. ETC ETC. Sorry for the long post guys.
I personally will continue to accelerate rapidly with my single piece Forged Motorsport Double Spoke rims.

[Boosted]

Originally Posted by SQ Bimmer

I think it looks pretty stupid, especially that car with the 17x10s. It looks like something I would see in South Central LA on a pickup truck.

Mini truckin', ahh yahhh. Although I do think it looks good on some BMWs (when not toooo extreme), ultimately not an ideal setup for most of our cars. If it's the look you want, well go for it then!

[egk2]

Well the reason I asked if you can back your claims is that forums
are full of misinformation, I'm sure you can agree. Again, we can beat this
topic to the ground but your claims are unsubstantiated, loss of grip for example, I haven't experienced any loss of grip or directional stability.
Also you mentioned unsprung weight, this doesn't only apply to wider wheels,
narrow wheels that are taller than original equipment also suffer from additional unsprung weight as well as increased rotational mass.

Btw your forged m3 wheels aren't exactly light weighing in at 19.7lbs for the fronts and 20.7lbs for the rears, while my "wide" wheels 16x9's weigh in at
18.1lbs.

[ozbmw]

Seems I have been wrong about the "Stretched Look", maybe its the way of the future to put undersize tires on oversize wheels. Puzzles me that M GmbH, BMW AG, Michelin, Goodyear and several other high profile companies like Dunlop haven't got on to this revelation in wheel setup. I will save a fortune by putting 195/50 r 17s on my 8.5" rims in the future. Thanks for the tip.
This is an exerpt from Dunlop Corporations recommendations for rim width: I know you won't believe it without concrete proof, I'm sure an E30 with 215 tyres tacked onto 9" rims is a better setup anyway.
"RIM WIDTH
Correct rim width ensures flex at the designed flex point in a tire sidewall for optimum tire performance.
If the rim is too wide, the flex point moves towards the rim area, causing heat buildup in the lower sidewall, which reduces tire life and could result in failure. Either too narrow or too wide of a rim can result in uneven tread/pavement contact pressure causing uneven wear and potentially reduced traction, or increased vulnerability to bead dis-lodgement. "

Wider rims may offer some performance advantages over narrow rims. A wider rim increases the distance between the beads, which results in a straighter sidewall, which stiffens it. This results in quicker steering response and higher cornering forces.
Negatively, the straightened sidewall transmits more road shock to the wheel and suspension, placing greater stress on chassis and suspension parts and delivering a harsher ride. The straighter sidewall exposes the rim, making the wheel more susceptible to damage.

[KetteringTi]

Ya can't really argue with that...

[EEEEeeee36]

Originally Posted by SILV3R

found this dude's car on bmw-sydikat. this is what i wish my car will have one day...
http://www.bmw-syndikat.de/bmwsyndik..._Title=BMW+E36
17x10 with 245/35/17 rubber according to him. wonder what he did to make it work?

To make that work he did what they do on a lot of cars for 'show' in Europe - he cut and flared the arches. It requires fender modification - rolling fenders and stretching tires with neg cam will not get you to fitting 10's under the stock bodywork.