[Tex_X7]

Hey Guys,

I made a video comparing the weight of the Factory 755M (complete with stock tire/tpms from my X7 M50i) to a complete setup with a Savini SV-F4 and new tire/tpms.

If you are interested in how they compare, here is the video:

https://youtu.be/wwnF23ZH3Ww

Thanks,
Hanz

[sliu070]

Can't open youtube at work. I can I get a TL;DR?

[Ken750iX7]

Originally Posted by Tex_X7

Hey Guys,

I made a video comparing the weight of the Factory 755M (complete with stock tire/tpms from my X7 M50i) to a complete setup with a Savini SV-F4 and new tire/tpms.

If you are interested in how they compare, here is the video:

https://youtu.be/wwnF23ZH3Ww

Thanks,
Hanz

Congrats! on your X7 M50i & Savani SV-F4

Thanks for your extensive info on Weight Comparison, you're the man!

[thenew3]

Originally Posted by sliu070

Can't open youtube at work. I can I get a TL;DR?

Savini VS Factory
front 70.6 / 76.2
rear 73.3 / 84.2

[MB21]

Originally Posted by thenew3

Savini VS Factory
front 70.6 / 76.2
rear 73.3 / 84.2

Is the strength compromised with significantly reduced weight?

[BMWBear]

Originally Posted by MB21

Is the strength compromised with significantly reduced weight?

Load rating of a wheel is more important then weight when determining strength. The aftermarket wheel could be made of or made by a manufacturing process (cast, flow formed, forged) that makes it stronger even though it’s lighter then a heavier wheel.

[MB21]

Originally Posted by BYEIL

Load rating of a wheel is more important then weight when determining strength. The aftermarket wheel could be made of or made by a manufacturing process (cast, flow formed, forged) that makes it stronger even though it's lighter then a heavier wheel.

The strength is determined by material, the process is used and design, if you shave 10lb it is a lot of material gone so your cross sections are much smaller therefore the strength might be affected unless compensated by material, typically you would need to go to Ti alloy to compensate for reduced cross sections on Al

Stock wheels are build to cope with generic use of daily life, anytime you move to performance options you gain something and lose something, as they say there is nothing such as free lunch

All what I was suggesting that out of the two seasons for winter I would go for something stronger due to more surprises on the road while summers are more easy on the wheels from impact perspective.

[Tex_X7]

Savini claims these are stronger...stronger than what?, who knows, haha. Being in Texas these will be my wheels year-round and we have our share of goat trails. I'll let you know if I have any issues.

[BMWBear]

Originally Posted by MB21

The strength is determined by material, the process is used and design, if you shave 10lb it is a lot of material gone so your cross sections are much smaller therefore the strength might be affected unless compensated by material, typically you would need to go to Ti alloy to compensate for reduced cross sections on Al

Stock wheels are build to cope with generic use of daily life, anytime you move to performance options you gain something and lose something, as they say there is nothing such as free lunch

Very similar to what I just posted but just because you lose material doesn't mean you lose strength. Depends on what you're comparing. If you're comparing two like wheels built with the same material and using the same process that would be true. If you're comparing two wheels and the second wheel weighs less but is using superior material and process then most likely it's not true.

If you're paying for quality aftermarket wheels your gains are not free. They're actually quite costly.

[MB21]

Originally Posted by BYEIL

Very similar to what I just posted but just because you lose material doesn't mean you lose strength. Depends on what you're comparing. If you're comparing two like wheels built with the same material and using the same process that would be true. If you're comparing two wheels and the second wheel weighs less but is using superior material and process then most likely it's not true.

If you're paying for quality aftermarket wheels your gains are not free. They're actually quite costly.

Great, what is superior material and process? Marketing is easy to do but reality often is brutal, most vendors will use same Al alloys as certified materials for same application, so I am curious on some data to see material properties and part properties as measured side by side, then we can say something is better. The fact that they say we use superior material means nothing

Sorry for reality I deal in this business and I have seen a lot of marketing nonsense

[BMWBear]

Originally Posted by MB21

Great, what is superior material and process? Marketing is easy to do but reality often is brutal, most vendors will use same Al alloys as certified materials for same application, so I am curious on some data to see material properties and part properties as measured side by side, then we can say something is better. The fact that they say we use superior material means nothing

Sorry for reality I deal in this business and I have seen a lot of marketing nonsense

You work in the wheel manufacturing industry or marketing? If you work in the latter you should not generalize all manufacturers of goods.

Wheels need to meet certain criteria outlined by governing bodies and could face heavy fines if their manufacturing process doesn't meet a standard today, tomorrow, 5 yrs from now and so on. These companies can face steep fines and/or be shut down if they're found to be doing things that would negatively affect the safety of the product. There's a plethora of information online about it. Certain wheel manufacturers like HRE have made videos about their process and re-certify their process more often then required. Some companies like them go above and beyond but as I said before you're going to pay for it.
https://www.youtube.com/watch?v=yujW1mtjVD4

If you want to find out the difference between an X7 BMW OEM wheel and an aftermarket wheel you'll need to put in the research. The information is readily available so you just need to look for it.

[MB21]

Originally Posted by BYEIL

You work in the wheel manufacturing industry or marketing? If you work in the latter you should not generalize all manufacturers of goods.

Wheels need to meet certain criteria outlined by governing bodies and could face heavy fines if their manufacturing process doesn't meet a standard today, tomorrow, 5 yrs from now and so on. These companies can face steep fines and/or be shut down if they're found to be doing things that would negatively affect the safety of the product. There's a plethora of information online about it. Certain wheel manufacturers like HRE have made videos about their process and re-certify their process more often then required. Some companies like them go above and beyond but as I said before you're going to pay for it.

If you want to find out the difference between an X7 BMW OEM wheel and an aftermarket wheel you'll need to put in the research. The information is readily available so you just need to look for it.

Perfect answer without any details...

There is NO such thing as requirement for products to meet tomorrow's standard, as law does not works back, so if new standard is applied the NEW products have to follow up but not the old, the old might get defined end of life cycle if not adopted.

I am not in wheel industry However I deal with manufacturing industry from cars to aero and so on (technology side) there is a lot of regulation and unfortunately those regulations might have nothing to do with what you described.

ie. wheel manufacturer is required to x-ray every wheel to look for cracks and porosity however this does not answer the question of which wheel will better survive the impact of put hole, because this is governed by minimum that has to be met, now the question is that both manufacturers can meet the min requirement, one can have hefty margin while the other will not. Both will have certified process and proven to end user that they follow leading standard. They both might get 5 star rating but products could have very different performance

My point with the wheel is that if you looking for sport then weight reduction will improve your car performance but if you look for good performance but better resistance to impact then more material and thicker cross section will prevail. So there is no perfect universal formula here rather if you gain one thing you need to know it is at cost of something else.

[BMWBear]

Originally Posted by MB21

Perfect answer without any details...

There is NO such thing as requirement for products to meet tomorrow's standard, as law does not works back, so if new standard is applied the NEW products have to follow up but not the old, the old might get defined end of life cycle if not adopted.

I am not in wheel industry However I deal with manufacturing industry from cars to aero and so on (technology side) there is a lot of regulation and unfortunately those regulations might have nothing to do with what you described.

ie. wheel manufacturer is required to x-ray every wheel to look for cracks and porosity however this does not answer the question of which wheel will better survive the impact of put hole, because this is governed by minimum that has to be met, now the question is that both manufacturers can meet the min requirement, one can have hefty margin while the other will not. Both will have certified process and proven to end user that they follow leading standard. They both might get 5 star rating but products could have very different performance

My point with the wheel is that if you looking for sport then weight reduction will improve your car performance but if you look for good performance but better resistance to impact then more material and thicker cross section will prevail. So there is no perfect universal formula here rather if you gain one thing you need to know it is at cost of something else.

Did you bother looking at the video? Ever heard of ISO9001, QS9000, TUV of Germany or VIA of Japan. You’re the king of generalization with blank facts to back then up. AGAIN if you’re comparing like for like your statement would be true but if not there are too many unknown variables to throw a banket statement on the outcome.

[MB21]

Originally Posted by BYEIL

Did you bother looking at the video? Ever heard of ISO9001, QS9000, TUV of Germany or VIA of Japan. You're the king of generalization with blank facts to back then up. AGAIN if you're comparing like for like your statement would be true but if not there are too many unknown variables to throw a banket statement on the outcome.

Sorry to say I do not think you have good picture about standards, let me explain.

ISO 9001 in very general terms is so called quality management system which has nothing to do with properties and quality of the product such as wheel itself. Check out first the iso.org site before citing marketing materials

9001 "This standard is based on a number of quality management principles including a strong customer focus, the motivation and implication of top management, the process approach and continual improvement. " how this relates to properties of the alloy or wheel?

Yes I am well aware of quality standards and what they are for and which governing bodies define the standards. I have been part of ISO and ASME meetings as well. I know people like to believe that if something is ISO certified then is the best, NO it only means that someone followed certain process which has nothing to do with the functionality of the product itself!

Let me give you analogy that is generic enough that should give good understanding how standards work

Booking 5 star hotel most people would think they book the best, thinking of how nice and clean and so on it will be, however 5 star has nothing to do with new or clean, it is standard that defines what amenities you have, do you have mini bar in the room or not etc. you might get 3 star that is cleaner and nicer than 5 star if the 3 star is brand new and 5 star is run down.

I have mentioned before and I will repeat I am in the manufacturing industry to be more specific focusing on quality aspects of what is produced, from aerospace to automotive electronics medical and so on, and I operate globally, trust me you might not like what you hear but this is the reality,

To be very clear all standards are very important, however their job is not what you think it is. Sorry

[Thumbs]

edit-- That video explains it pretty well!

Great discussion and I would like to add my 2-cents.
Here is my understanding of it all- feel free to correct, clarify, etc.
ISO-9001, etc. are, as stated, process protocols which "merely" state that the company has certain procedures in place to ensure that whatever they "produce" is done so in a certified manner. It does NOT make any guarantee as to the ability of the product to pass some durability, etc. test unless that test has been passed and the company claims the product meets the standard.

Wheel durability, impact resistance, etc. are probably covered by a variety of ISO, etc. standards-- I have no idea which. If a manufacturer tests their wheels and claims they are certified to standard A10, which is better than A9, and they manufacture under ISO 9001, etc., then the consumer has a reasonable expectation that every wheel of that model will meet the test criteria.

An OEM wheel weighing 36 pounds is likely to meet a very high standard of impact resistance, etc. A 26 pound high-performance wheel intended for racing may not need to meet the same impact standard as an OEM wheel, yet needs to meet a different set of criteria such as heat resistance, lateral-load resistance, etc. They are both strong, but in different ways.

Is the high-performance wheel suitable for an SUV? Beats me!

Is a light-weight wheel built to the same standards as the OEM wheel as strong as the OEM wheel? If it passes the same tests then it is hard to argue otherwise.

The big question-- how do we know which wheels are up to the task of supporting an X5/X7 vs. M2?

[MB21]

Originally Posted by Thumbs

edit-- That video explains it pretty well!

Great discussion and I would like to add my 2-cents.
Here is my understanding of it all- feel free to correct, clarify, etc.
ISO-9001, etc. are, as stated, process protocols which "merely" state that the company has certain procedures in place to ensure that whatever they "produce" is done so in a certified manner. It does NOT make any guarantee as to the ability of the product to pass some durability, etc. test unless that test has been passed and the company claims the product meets the standard.

Wheel durability, impact resistance, etc. are probably covered by a variety of ISO, etc. standards-- I have no idea which. If a manufacturer tests their wheels and claims they are certified to standard A10, which is better than A9, and they manufacture under ISO 9001, etc., then the consumer has a reasonable expectation that every wheel of that model will meet the test criteria.

An OEM wheel weighing 36 pounds is likely to meet a very high standard of impact resistance, etc. A 26 pound high-performance wheel intended for racing may not need to meet the same impact standard as an OEM wheel, yet needs to meet a different set of criteria such as heat resistance, lateral-load resistance, etc. They are both strong, but in different ways.

Is the high-performance wheel suitable for an SUV? Beats me!

Is a light-weight wheel built to the same standards as the OEM wheel as strong as the OEM wheel? If it passes the same tests then it is hard to argue otherwise.

The big question-- how do we know which wheels are up to the task of supporting an X5/X7 vs. M2?

Great comments I like your added explanations. Like you said you can have product that meets all ISO and still could be bad

If I can add one more thought. The large OEMs have to be conservative as they are under heavy legal watch one mistake can cost a lot, while third party making custom parts is under very different scrutiny. At least this is how I see it.

[BMWBear]

I guess Takata was immune to that OEM scrutiny. If we were to list all the significant failures of OEM parts over the years we’d run out of internet space. Bottom line is if you want an aftermarket part do your homework. If you’re that worried that an aftermarket part will fail then don’t buy one. Simple.

[xueju1121]

I checked the maximum loading index on 22' Savini, they are 2,200 lbs each, so I think it will be fine to support X7.

[Influence]

You posted the sizes, but what model tire are they specifically? Did you switch to non-runflats? Were the stock tires runflats?

[ppagiga]

Originally Posted by xueju1121

I checked the maximum loading index on 22' Savini, they are 2,200 lbs each, so I think it will be fine to support X7.

i don't have a horse in this race, just wondering, if the x7 v8 weights 6000 lbs, 1500 at each corner, what's the maximum load any one wheel will experience given a range of outcomes?

off-roading you may exceed that 2200, but otherwise the likelihood is low, is that correct?

as for bmw's rims, no idea what their load rating is.

[Thumbs]

I think the load rating becomes an issue for a max weight (full of cargo) vehicle towing something heavy. The GVWR of the X7 is ~7,000, model dependent. Divide that by 4 wheels to get 1,800#/wheel (using 7,200#).
I'm not an engineer so this may be completely wrong! Under acceleration, with a trailer attached, I would guess the load on the rear wheels would be significantly higher than 2,000#/wheel but perhaps the suspension handles it all somehow.

[dmanb2b]

Well this was an interesting read. That weight savings is significant and should only improve the ride with such a large reduction in unsprung weight.

As far as OEM wheels, unless they are forged (think true M cars) BMW has historically made some of the softest and heaviest cast alloy wheels...constantly bending or cracking with runflats. Moving to a rotary forged or fully forged wheel won't increase the risk of structural wheel damage, if the load rating is similar or better than OEM spec.