its funny cause you sure sound like you know what your talking about but in reality you don't. I had similar arguments with you on the thread e85 in an Amg. Guess what you disagreed with me till you where blue on putting e85 on our cars saying won't work this and and that. You didn't want to believe me that there was a kit coming out making gains. Guess what been running a flex kit on my car with 100 percent e85 (not the exact ethanol content) in my car for the past 5 months. Noticed major gains and car runs like its on 93. So I know this might be crazy concept but your not always right.

 

I tend to side with the person who knows how to use proper spelling, punctuation and grammar. And has mountains of real-life experience. Just saying.

 

Good for you👍🏻

http://thesquealingtire.com/hub-centric-rings-defined/

 

Really? I guess everthing I and a multitude of other engineers and scientists have ever learned and seen over the years must be wrong then.

One of my best friends who has worked for Rolls-Royce Aerospace examining and studying metal failures all his life is sitting 20' away and I just asked him just in case... he says if you're right he'll have to sell his stock in the company, immediately resign and get a new profession as apparently the whole science behind his job is now null and void thanks to your research. He is kindly asking that you share your sources though...

 

Ugh... your source is a "tire expert" of Discount Tire Co. (who sells crappy aftermarket wheels and rims for a living)?

 

yeah and your source is you and only you. O and a random guy. I'll take their word for it. How about tire rack you like them? It's for alignment purposes only.

http://blog.tirerack.com/blog/turk-t/custom-wheel-fitments

 

Just a quick primer on hub-centric vs. lug-centric wheels: https://www.thoughtco.com/hub-centri...wheels-3234497. You might want to read the second paragraph (HUB-CENTRIC).

 

I am not about to get in a pissing match, but if you Google "Hub-centric wheel load" and read any of the first half-dozen hits, all should give you a straight-forward explanation of what carries the vertical loads in a hub-centric design. You of course are free to believe otherwise... but please refrain from giving incorrect and in this case outright dangerous advice to others. Why do YOU think the OP's bolts sheared?

 

well for one not sure on how reliable that website is. That could be your submission for all I know. I understand hubcentric vs lug centric thanks. This is my question for you. I will agree that a hubcentric wheel is preferred because the hub exactly matches the hub of the car it's going on. Metal to metal. Clearly the best of the two. However most rims arnt like that and it is an acceptable practice to use hub rings just like your article states. Making lug centric. end result a spacer is placed to fill gap. No more gap. Both versions are now the same at this point just a spacer is there. No where did it state this was not acceptable. If what you believe to be true is the hub rings holds the weight of the vehicle. How are the hub rings supporting all that weight. And then why are people who I'm sorry but they do, specialize in strictly rims and tires allowing this practice. As well as specifically stating its used for centering of the wheel, which in term prevents vibration, which in tern prevents stress on the lug bolts. Btw the metal hub rings are just as flimsy as the plastic ones. Do explain.

 

just stop now. What dangerous information am I giving? I'm saying hub rings don't hold the load and are for centering purposes I have multiple reliable sources backing up my claims. No dangerous info here. As far as why they sheared. A combination of an un centered wheel with either over torqued or under torqued bolts. On top of them being most likly sub par lug bolts.

 

http://www.maximummotorsports.com/te...s_spacers.aspx

http://www.eng-tips.com/viewthread.cfm?qid=152939

 

so its the friction of 3 parts together. The hub which is load bearing, the rotor, and the wheel.

when you change your rotor there is a small screw that needs to be taken out to change, how can that alone hold keep the rotor in place when you are under max braking power? so the bolts are not what is load bearing it is the friction between the wheel and hub.

its like putting your hands together force it tight then try and move one hand up and one hand down. you can feel the friction.

i just made all this **** up

 

The dangerous information you are giving is in bold in your quote above. Your multiple "reliable" sources are NOT reliable sources. See the links from tpliquid, and here are a couple more:

http://www.machinedes********/fasten...centric-wheels (written by a Ph.D. & P.E. with primary experience in the field, like my friend but not by him... complete with pictures of sheared bolts)

https://www.physicsforums.com/thread...wheels.764338/

http://www.croberts.com/Automotive-wheel-detachment.htm

http://corvaircenter.com/phorum/read...,852190,page=2 (this one addresses the post you quoted at thesquealingtire.com site)

http://driving.ca/auto-news/news/why...b-centric-rims

And here's a tidbit from your experts at the Tire Rack about track wheels (https://www.tirerack.com/wheels/tech...jsp?techid=110&) - gotta love how it is important when it suits them:

Since almost all of today's cars are designed with hub-centric wheels which transfer the vehicle's load from the center of the wheel to the car's hub (and allow the lug nuts/bolts to just hold the wheel against the hub), it is important that track wheels continue to be hub-centric to help distribute the forces encountered on the track. If an aftermarket wheel requires special centering rings to properly fit it to the hub, be sure they are installed correctly.

 

First tpliquid post was on hub spacer not ring. The one post you posted talked about the use of a hub ring I agree it should be used. End result is this the hub ring is for mounting purposes and ensuring the rim is centered. So you don't get what the pics showed in your threads of the guy that didn't use them due to vibration. Just like your posts in the e85 thread you are always right until your not then your quiet.

 

Re-posting the MachineDesign link. The one above didn't work because this forum kills the link. Remove the space in the link below.

http://www.machinedesign .com/fasteners/what-s-difference-between-lug-centric-and-hub-centric-wheels

It's as legit as it can get. The C63 is a hub-centric design. Do what you want though...

 

still didn't work but I pulled it up. The argument was not what was better. I was only saying that hub rings are for centering the wheel only not for bearing weight that's it. Obviously hubcentric is better and I said that already. I'm not arguing that fact

 

AS WELL AS SUPPORTING THE WEIGHT OF THE VEHICLE.

YOU DO GET SHEARED BOLTS WHEN THEY SUPPORT THE WEIGHT OF THE CAR - WHICH THEY WEREN'T DESIGNED TO - IN A HUB-CENTRIC APPLICATION.

NOT DUE TO VIBRATION. DUE TO LATERAL, SHEARING FORCES BEING APPLIED TO THEM.

AGAIN, NO. I AM GOING TO BE QUIET BECAUSE MY HEAD STARTS TO HURT AFTER (HOPELESSLY) TRYING TO REASON WITH SOMEONE AS STUBBORN AS A GOAT.

 

For the last time - the hub flange IS FOR BEARING WEIGHT.

 

Takes a stubborn person to know a stubborn person.
Hub rings plastic or metal are not designed for bearing weight. Centering rim only. Thankyou I'm done.

 

stub·born
ˈstəbərn/
adjective
adjective: stubborn

1. having or showing dogged determination not to change one's attitude or position on something, especially in spite of good arguments or reasons to do so.

I am afraid you haven't presented any good arguments or reasons for your point of view (whereas I have, as have others), so while it is possible that I may be stubborn, based on this particular exchange you have no basis whatsoever to arrive at that conclusion.

You ARE correct that the crappy PLASTIC hub rings are not designed for load bearing. You ARE NOT correct that the METAL ones that permanently clip in the wheel hub like the ones that BBS or OZ Racing use in some of their wheels are not designed for load bearing - they most certainly are. At least that's what one of the engineers at the OZ Racing HQ & plant in San Martino di Lupari in Italy told me a couple of years ago when I visited the plant, although I suppose he too could have been reading things on the Interwebz or possibly even lying.

 

i provided plenty of arguments backed by people that work with tires and wheels all the time. You just believe what you believe. Your stubborn and frankly annoying with your definition of stubborn. Your arguments where posts on the differences of hubcentric vs lugcentric not what I was even talking about its fine. You think what you want. I'll know the factual information. O yeah and you really don't think a wheel company is going to tell you that cause they want you to buy their rims. Especially considering your views on lugcentric vs hubcentric. Of course they would tell you that. Another thing everyone you talk to is a specialist it's crazy. Might want to find some new people if your talking to the same ones you got your information about e85 and our cars. Might not be reliable facts.

 

Just have to C&P then remove the space before the ".com"

The hub does support all the weight in the C63 design. That's why the OEM wheel fits snug around the hub. Possibly what happened to the OP?

If you don't use a hub-centric wheel, the below can happen which is clearly stated in the machinedesign article. OR the extra stress on the lugs (which they're not designed for) could break them.



I'm not understanding why there's an argument here. If the C63 had a lug-centric design, it would likely have larger lug bolts to handle the extra stress.

But, it doesn't and you shouldn't convert between the two. It couldn't be any more black and white...

 

 

Hi folks... I read through the email threads above on the topic and wanted to share my experience just this weekend... I have 17" AMG wheels on my 2003 C230 Coupe that originally had 16". The new (rear) wheels are wider and rubbed on the "inside' of the rear, so I got wheels spacers. The wheel spacers have an enlarged recess on one side and a protruding Lip on the other side so that the "hub-centric" feature is retained. I should also mention that the spacers are a full inch (25mm) thick to get the "look I wanted. The full 25mm thick spacer meant that I would also need longer wheel bolts. However the wheel bolts are actually only 20mm longer than the stock ones since the new wheels themselves are not as thick at the mounting flange. So far so good.
I went on Ebay and bought a set of longer Chrome wheel bolts - to match the Chrome wheels - and yes, I got the correct head design which is SPHERICAL... which matches both the stock and new wheels. Again, so far so good. Well after driving on them for about 4 months, I was walking up to my parked car at night around midnight and noticed that 3 of the 5 lug bolts were "dark" - not shiny like the other two as expected. As I got close and took a good look with my phone flashlight, it turns out that the dark bolts were actually "MISSING" bolts! Yikes I had just driven to my destination with only 2 of 5 wheel bolts holding it all together. I should let you know that, besides being a schooled Mechanical Engineer with a Master's degree, I am a long-time "car-guy" and have worked on cars for at least 4 decades. I can say to all of you that there was ZERO strange vibrations coming from the rear or anywhere else on the car in my last drive to this destination and that I was traveling at around 75mph on the freeway. I suppose this is a testament to the "hub-centric" features doing their job.
In the dark night I used the factory jack and lug wrench to remove the chrome wheel and put on the spare. I had the foresight to keep 5 of the stock wheel bolts in a bag with the spare since I knew the longer wheel bolts wouldn't work if I ever needed to put the spare on - like now. I removed the chrome wheel and spacer and found that the three missing bolts had actually SHEARED OFF (below flush!) and were now blocking me from installing the stock wheel bolts - UGH! I Uber'ed home and returned the next day with a proper floor jack, drill , drill bits, and easy-outs to extract the broken studs. About 5 seconds of drilling let me know these were hardened bolts and that my drill bits were no match for the hardened steel - UGH #2! Miraculously, I stuck a simple screwdriver into the hole and swirled it around on the face of the sheared bolt and it actually moved! using this motion I amazingly was able to get ALL THREE broken bolts out (what luck!).
I reasoned that the "Chinese" chrome bolts were over-hardened to the point of being "brittle" and that they had failed from me under or over tightening them. I originally bought a set of 20 bolts and still had 10 at home. So I took 5 and this time tightened them carefully in two stages using a torque wrench, and decided to "keep a close eye on them". within a few weeks I found one bolt broken again, so I stopped driving the car and ordered some high quality "German made" wheel bolts from a local tuning shop that does lots of work on Mercedes' - I figured they would know what to get for me. The high grade bolts arrived and I installed them - again they were the right head shape (spherical) and I tightened them in two stages to their recommended torque of 100 ft-lbs. Everything was fine a for a couple more months, when I lent my car to an out-of-town visiting friend for the weekend. I was a bit tired from staying up late the night before and I was woken from my nap with a loud truck in my driveway... a quick glance out the window and I could see it was my car being delivered on a flatbed tow truck with the spare tire mounted on the rear and held on with only a single lug bolt! Apparently the wheel bolts had failed to the point of coming off on the freeway!!! Thank God no-one was hurt and the rogue wheel was found a few hundred yards away and managed to not hit anything or anyone!
I used my torque wrench to check the other rear and one of those bolts was sheared off - still sitting in the hole but not doing anything - leaving 4 of 5 holding that wheel on. This gave me a good scare... OK, what to do? I really like the chrome wheels, but I don't want a dangerous car! As a mechanical engineer, this is not making much sense to me either... this is not a heavy car and the high grade bolts should easily be able to withstand the forces of normal driving. One thought is to upgrade (drill and tap - I am also a machinist with my own machine lathe and Bridgeport mill) the hubs to accept the 14mm diameter bolts found on larger Mercedes cars (my C230 has the 12mm x 1.25 bolts). In addition I think I will change to thinner wheel spacers (15mm) to reduce the "mechanical leverage" against the wheel bolts.
So just to summarize, I used the correct bolt head shape (spherical), followed the best practices of two-stage torquing with a torque wrench, used high-grade bolts, and tightened them to the recommended spec, and still had failures. As a mechanical engineer, I know the bolts were loaded in pure tension (with the hub-centric" features). The car is not very heavy, nor does it put out much torque. This just does not seem to make sense engineering-wise... Hmmm... Not ready to give up yet, but also don't want a dangerous car on the road... I appreciate your thoughts and I will also let you know what happens next...
Cheers! Vm

 

Are you serious