Which is the strongest?

Stock wheel(s)

Aftermarket cast wheel(s)

Aftermerket forged wheel(s)

Would it be fair to say the for the most part the heavier the cast weel the stronger?

How much stronger are forged wheels?

Would it be possible for a heavy cast wheel to be stronger than an extremly light weight forged wheel?

 

usually forged wheels are stronger and lighter than cast wheels.
But it will be hard to compare a heavy cast wheel and extremly light weight forged wheel, since it most likely depends on many factors such as manufacturing. a cheap heavy cast wheel won't be as strong as a high quality light weight forged wheel. but a nice quality cast wheel might be stronger than a medium lightweight forged wheel.

 

Again, forged is stronger and lighter than cast. They also tend to be at least 50% more expensive too. You get what you pay for.

 

I would say that it depends on what your measurement of strong is.

Forged is stronger than cast yes. BUT it is only lighter because the added strength allows the use of less total material.

So... is a forged wheel "stronger" than a cast wheel? Not necessarily. If you're talking about something like bends from potholes, then I'd say no... they're typically not any stronger. If, however, you're thinking about spoke breakage, or cracking, then I'd say that the forged wheels are almost always better.

 

The strongest method of wheel manufacturing is Forged.

Stock wheels tend to be gravity cast due to lower cost/moderate weight and durability.

Strength in a cast wheel depends on how it was designed and built(more than one way to cast a wheel exists)- more mass does help it to resist damage in general.

If you compare a high quality wheel like the SSR Comp in 17" to a stock 17x7" MINI wheel the SSR is both stronger and lighter. It's hard to give it an absolute number. However any wheel no matter how strong can be damaged if a big enough obstacle is hit with enough speed. Anyone with light wheels needs to drive carefully to avoid road hazzards or pay the price in repairs or replacement wheels.

It is possible for a heavy S-lyte wheel to be more "durable" than a very light 11 pound cast 15x7" Kosei K1 TS rim. Does that mean stronger? Yes, resistance to damage under normal use could imply stronger. Another factor is what tires are used. When runflats are used with the S-lytes the rims are prone to damage since the runflat sidewalls are so stiff and transmit damage to the rims. If a non runflat tire is used with a taller sidewall that would help absorb the force- this would apply more to 16 and 15" rims.

See
http://www.tirerack.com/wheels/tech/construc.jsp

 

Sounds like you may have contradicted yourself here.

I'm a huge fan of the SSR Comp, and while I don't think it's as fragile as many say, I have a hard time believing it's stronger than the stock cooper wheel. Subjected to the same stress my vote would be for the SSR to bend first. Of course, this is pure speculation. I just think it's important to distinguish between strength of the material (forged metal vs cast metal) and the strength of the finished product (superlightweight wheel vs heavy wheel)

 

Yes, there is the problem. Inch for inch of material the forged wheel is "stronger and lighter" (more dense) but the finished product may or may not stand up to daily real life punishment on our roads.

Why don't you call Alex@tirerack.com and ask the question? When I've talked to him about the SSR comps the discussion came down to- to get wheels to be that light you are paying for a manufactoring process that is high tech and of high quality. It is still going to be a very light rim and subject to damage. Performance may be enhanced, but at the cost of durability.

The cheaper stock rim is less expense to produce and allows for good strength by being robust in design and in mass. Performance would be sacrificed for durability. Neither rim is totally bullet proof to potholes.

I know many many MINI owners in my area that have damaged runflat tires, non runflats, and stock S-lyte rims on potholes. I have my 14 pound 17x7" rims and non runflats that I have driven for over two years with no damage whatsoever. I do hit some potholes occasionally but nothing too major.

 

The spokes of the wheels that minihune have are prone to cracking when used in racing because the forgings are sub-standard. That said, I have seen very few incidents of MINI S-lites bending no matter what they hit (hence their nickname "boat anchors"). SSR Comp's are a very nice race wheel, but the polished lip bends easy if it hits a pothole on rough streets. Wheels that have the spoke flush with the lip seem to be less prone to bending via pothole or curb than those with a "deep dish" lip.

I've seen bent wheels on the MINI from 15" "holies" to 18" aftermarket and everything in between. Nothing is immune if you hit it hard enough.

IMO, this is a bad thread. We can only slighly generalize this topic before we start blowing smoke. My question to royce is: beyond the hypotheticals, what's your actual question?

 

For what it's worth I have used 17" & 18" SSR Comps. on my E46 M3, two other BMW's (E46 coupes) and my two Mini Coopers w/ narry a problem. In the almost 4 years since I started using the SSR Comps. on my cars I have subjected them to street, track and aggressive backroad driving on some very imperfect road surfaces. IMO without a doubt the advantages of running a strong and lightweight wheel trumps any theoretical disadvantage. Get the wheel you want and drive carefully.

 

I would agree with Ryan that this thread is misleading.

And yes, it is correct that some owners of Centerline RPM wheels have had failure of the spokes then used on the track(this was reported to Centerline). I have run mine and another MCS owner has run his on the track for 2 years and neither of us had ever had any problems with our wheels. Quality control issue??

Wheel design plays a major role in resistance to damage. Always be careful whether on the street or at the track. Strength can help you only so much.

 

I rolled my '03 MCS twice from the track on to dirt at about 100 MPH. I have SSR's and when they hit the dirt, they dug in up to the axels on the passenger side and half that much on the drivers side as we went over again. The car was totaled, driver and passenger had not a scratch and the SSR's are almost true. The wheels dug in emough to force gravel between the tire and rim at 36 PSI. The wheels are scratched, but ture enough to run on the track, but probably on the highway they would be rough. for SSR Comps.

 

Denser and lighter - now that's a neat trick. I believe you are mistaken.

Back to the SSR's... I too have had good luck with the wheels. Track/street/whatever. Over on the honda boards a rumor got circulated that Realtime racing bends and throws away something like 30+ wheels per season. This has contributed a lot to the feeling that they're weak. I don't know if it's true or not, but even if it is... 1000lb+ springs plus street tires plus bouncing over curbs on the track is going to be tough for any wheel to handle.

I'll eventually put a set on the Mini. I'm trying to decide whether to run 17's or go back to stock brakes with 15's. I guess I should have though about that before I sold the two sets of 15's I had right before buying the car.

 

If SSR's weren't good I wouldn't be buying them year after year on
my various cars. :smile:

 

JeffS,
Sorry, you can talk to Alex@tirerack for the full story; to quote tirerack's tech article on Forged wheels-
"The ultimate in one-piece wheels. Forging is the process of forcing a solid billet of aluminum between the forging dies under an extreme amount of pressure. This creates a finished product that is very dense, very strong and therefore can be very light. "

So how can this "neat trick" be true?
If your more dense material is used in a wheel that has less total volume (an open spoke or thinner spoke design) then the wheel can be both strong and very light. Many of the cheaper forged wheels are a bulkier design. Now that is good wheel engineering for you. I guess you get what you pay for.

 

Having owned many Forged aluminum wheels, 3 sets of Volk te-37's (15's & 16's) plus a set of 16" ce28n's, 5 sets of SSR comps (15's, 16's & 17's) and 1 set of Racing Hart CP-035's I'd say the strongest of the LIGHT Wheels is the Te-37. Seems like they are made for Racing but just happen to be available for street use where the others are made for the street but you can race on them.

 

Good performance requires a excellent design, good materials,
good processes, good tooling, and good workmanship. Murphy
always finds the weak link. Period.

"Match the need with the proper product".


If you want more info I have a PDF file that will "briefly" break it down...
It seems I cannot attach it due to the size and it also seems you cannot attach a zip file here...


-kutch

 

minihune,

I also have the Centerline RPM wheels, where on the spokes did the cracking occur? Was this a recent problem or older? I have had my wheels for about 1 year (but only 1 track day so far) and haven't noticed a problem (yet). The wheels are off due to brake upgrades so it will be easy to check them out when I get home tonight. Hopefully all will be ok

 

i didn't mean to start a bad thread. thing is i'm 18 and don't have the money to go buy an expensive set of wheels and have them bend on me. i have it when you can't get a wheel balanced on the highway. i would gladly trade some weight for a smooth ride on the highway. i'm about to switch tires and maybe wheels - it makes sense to do them at the same time. right now i have the stock 16" 5-spoke design with the 195/55 runflats. i may lower the car in the future so, i'm trying to keep that in mind. i want a tire with a mileage warranty for everyday driving. i love bfgoodrich. i'm leaning towards putting the 205/50 traction T/A on my stock 16" wheels. i'm hesitant to get rid of the stock wheels. i've gotten a lot of complements about them including from other mini owners (guys with slites). while 15s are good for autocross and 17s are good fot the track 16s seem like a good inbetween for the street.

 

sanddan,

I sent you a PM. Essentially another owner had a spoke failure in the first two weeks when turning left. Not sure why this occured but Centerline refunded the owner for the whole set. I'd say it happened about a year ago. Randy Webb and Centerline know about his. I always inspect my wheels before and after using them on the track. I usually do wheel changes 2 or 3 times a month.

Royce,
For now you can just stick with the stock 5 spoke rims which will work fine.
They are not super light but not too heavy for MINI stock wheels. As you get more experienced you can shop around and decide what to do. Check out other MINIs and go for a ride when you can. The rim is only one part of the equation with the suspension and tires being the other big factors. Usually quality rims cost more but will last longer as long as you are careful and not run into a huge pothole or curb.

Last night I let a friend drive my MINI and we hit two potholes in about 10 minutes. The Centerlines did fine after inspection. Shucks, and I was looking forward for an excuse to getting new 19" wheels.