Strong RIMs [Archive] - Bimmerfest - BMW Forums

Strong RIMs

06-15-2012, 04:47 PM
A month after purchasing my certified 2008 535xi with Sports Pkg and 18" wheels, I felt a vibration in the pedals and steering wheel. The dealer tells me 3 of the 4 rims are bent. I know the roads suck around here, but never had any issues with previous BMWs. Any recommendations for replacement rims that are stronger? My previous BMWs' OEM rims were by BBS, these however are not. So I don't want to replace with the same OEMs.

ModBargains III
06-15-2012, 05:02 PM
There are several levels of construction, ranging from the least expensive way to make a wheel, also considered to be the least strong as well, to of course a very expensive strong wheel. Of course there will always be the opportunity to bend a really expensive well created wheel if the pothole is big enough, or if the item you hit is large enough, so we always recommend to watch out for these things.

Gravity cast wheels is the least expensive way to make a wheel, typically your average aftermarket wheel - most replicas.
Low pressure cast is a better construction giving better strength, a little less weight
Rotary Forged/Flow Formed - Essentially a forged barrel, with a cast fast, significantly stronger - typical range for what we suggest if you need a strong wheel.
Fully Forged Aluminum wheels - Typically very expensive, ranging from pricing to $5,000+ for a set of four wheels, but also very durable, and extremely lightweight.

I would suggest Rotary Forged/Flow Formed options like these for your best bet for a strong wheel: (
*Forgestar F14 Wheels for BMW 18" ( (
Forgestar CF5 Wheels for BMW 18"/19"/20" (

If you have any questions, don't hesitate to ask!!

06-15-2012, 06:12 PM
I would look for forged wheels - Beyern just came out with some that are not too expensive. Forgestars are awesome, too.

06-15-2012, 10:10 PM
it is quite simple.:)

Forged alloy wheels are stronger. They actually compress the metal and you get great strength.:thumbup:

BUT the reason you need material as strong as possible is that you insist on wheels with minimal metal "spokes", and large diameter.
If you look at the very boring stock base alloys they are VERY thick and are MUCH stronger.

when you hit a pothole with a heavy sedan there are tons of forces in play and the wheels will bend. The thick boring ones will have a greater chance for survival.

Yeah, but who wants those!!

06-16-2012, 05:30 AM
@ModBargains III - Thank you for education. What type do you think the OEMs are? I like the look of the F14 ones. Do they come in 19s? Will 19s fit on my car?

06-16-2012, 05:32 AM
@njlou - do you mean thicker than these?

06-16-2012, 05:33 AM
Are all forged wheels equivalent? BBS vs Forgestar for example.

06-16-2012, 06:29 AM
The ones in the photo look like the stock Style 124 that come with the 535 Sport sedan. I have those and had 3 of them straightened so far. Also replaced a rear that was bent on the outside where the spokes are! Those are BMW oem rims made by BBS.
Metro NY roads are a bitch.

If you go to 19s there will be less sidewall height and it will be even easier to damage the rims. Suggest you either fix the rims and live with it or upgrade to forged 18s. I used to straighten mine.($100 a piece, done on site.) I swapped a rear wheel via a shop in Long Island that took my old rim and gave me a perfectly reconditioned one for $200 total. It was like new and perfectly true.

06-17-2012, 09:42 AM
Are all forged wheels equivalent? BBS vs Forgestar for example.

Forgestar are NOT forged wheels. They are a modified form of low pressure cast wheels, slightly stronger than ordinary casting, but nowhere near forged. While they represent an acceptable compromise between low pressure cast and forged, the name is deliberately misleading IMO. Keep in mind, the strength of a wheel, or any structure for that matter, is a result of not only the material but also the design and shape of the center section. A wheel with a 5-spoke design utilizing a relatively thin contact area with the rim will be very prone to bending on rough roads, whereas the best resistance to deformation lies in the classic "honeycomb" design of the traditional BBS wheels.

06-17-2012, 01:49 PM
I'd go no larger than 18" wheels. Pretty much any aftermarket wheel is going to be stronger than the stock BMW rims, which are known for issues. Head down to discount tires. They'll give you a deal on something decent.

As for forged rims, you'll pay through the nose and get something lighter, but they usually used the increased strength per pound to make that lightness, so you don't get a stronger rim all the time.

While you're at it, replace the tires with non-runflats.

ModBargains III
06-18-2012, 10:51 AM
Are all forged wheels equivalent? BBS vs Forgestar for example.

If you're talking about fully forged aluminum wheels, then they are almost all alike. They're still in the upper echelon of strong and lightweight wheels.

Forgestar wheels are equivalent to the BBS CH-R's process of manufacturing wheels. Spun Cast, Rotary Forged, Flow Formed are all essentially the same process. BBS calls CH-R's Spun Cast, Forgestar says Rotary Forged, they're all the same process of manufacturing/constructing those particular wheels.
Go to 3:04 on the video!

The barrel as you can see if being forged by two arms that form the wheel, to elongate it. This significantly increases strength and keeps materials minimal to keep weight down.