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View Full Version : forged rims Vs. alloys


red-jdm
07-23-2007, 08:30 AM
guys, please tell us your opinion, forged rims OR alloy???

kimona
07-23-2007, 09:38 AM
Check this website: tirerack.com

Click on wheel tech, then wheel construction.

Unless you're racing your Vitz/Yaris, I think any quality wheel construction will be quite satisfactory.

ChinoCharles
07-23-2007, 10:50 AM
If you can afford forged, buy forged. If you can't, don't. That simple.

Thirty-Nine
07-23-2007, 10:57 AM
BTW, you're looking for the difference in between forged and cast wheels. Both wheels are going to be an aluminum alloy.

From Webster.com

Molten: A substance composed of two or more metals or of a metal and a nonmetal intimately united usually by being fused together and dissolving in each other when molten.

Biggie™
07-23-2007, 02:33 PM
BTW, you're looking for the difference in between forged and cast wheels. Both wheels are going to be an aluminum alloy.

I have some cast Magnesium wheels. :smoking:

Thirty-Nine
07-23-2007, 02:57 PM
Okay, so MOST wheels are alloy. :smile:

reznunt
07-23-2007, 03:01 PM
BTW, you're looking for the difference in between forged and cast wheels.

X2

they have different manufacturing processes and the cast wheel finished product ends up being heavier. i think it has to do with the tighter grain structure on the forged wheel. someone correct me if i'm wrong... it's been a long time since school.

Biggie™
07-23-2007, 04:38 PM
X2

they have different manufacturing processes and the cast wheel finished product ends up being heavier. i think it has to do with the tighter grain structure on the forged wheel. someone correct me if i'm wrong... it's been a long time since school.
Since no one wants to visit that Tirerack url, I'll post it.

Though not enforced, there are quality standards to govern the production of wheels. Some countries though, like Germany and Japan, have government regulations requiring aftermarket wheels to meet certain criteria and ensure proper fit. The United States has taken steps to establish guidelines but it will be some time before they can enact regulation of any kind.

Consequently, all wheels are not made the same. The performance of an alloy wheel is a direct result of the manufacturing technique employed.

The Tire Rack offers a wide range of wheel choices from manufacture's that have adopted the manufacturing processes that meet the strict O.E.M. (Original Equipment manufacturers) requirements. Wheel companies that supply to the O.E.M. market must follow certain procedures during the manufacturing process to maintain the quality and integrity of their product.

There are many factors to consider when purchasing an alloy wheel.

One-Piece Cast Wheels

This is the most common type of aluminum wheel. The casting of wheels is the process of getting molten aluminum inside a mold to form a wheel. There are different ways this can be accomplished and although it sounds simple, this is truly an art when done properly.

GRAVITY CASTING

Gravity casting is the most basic process of pouring molten aluminum into a mold utilizing the earth's gravity to fill the mold. Gravity casting offers a very reasonable production cost and is a good method for casting designs that are more visually oriented or when reducing weight is not a primary concern. Since the process relies on gravity to fill the mold, the aluminum is not as densely packed in the mold as some other casting processes. Often gravity cast wheels will have a higher weight to achieve the required strength.

LOW PRESSURE CASTING

Low pressure casting uses positive pressure to move the molten aluminum into the mold quicker and achieve a finished product that has improved mechanical properties (more dense) over a gravity cast wheel. Low-pressure casting has a slightly higher production cost over gravity casting. Low pressure is the most common process approved for aluminum wheels sold to the O.E.M. market. Low-pressure cast wheels offer a good value for the aftermarket as well. Some companies offer wheels that are produced under a higher pressure in special casting equipment to create a wheel that is lighter and stronger than a wheel produced in low pressure. Once again in the quest for lighter weight, there is a higher cost associated with the process.

SPUN-RIM, FLOW-FORMING OR RIM ROLLING TECHNOLOGY

This specialized process begins with a low pressure type of casting and uses a special machine that spins the initial casting, heats the outer portion of the casting and then uses steel rollers pressed against the rim area to pull the rim to its final width and shape. The combination of the heat, pressure and spinning create a rim area with the strength similar to a forged wheel without the high cost of the forging. Some of the special wheels produced for the O.E.M. high performance or limited production vehicles utilize this type of technology resulting in a light and strong wheel at a reasonable cost. BBS has used this technology for several years in their production of racing wheels for Formula One and Indy cars. BBS's RC wheel for the aftermarket is an example of a wheel produced using spun rim technology.

FORGED OR SEMI-SOLID FORGED


In forged wheels, computer numerically controlled
(CNC) mills add the cosmetics and the bolt circle to exacting tolerances.
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. The costs of tooling, development, equipment, etc., make this type of wheel very exclusive and usually demand a high price in the aftermarket. Semi-solid forging (SSF) is a process that heats a billet of special alloy to an almost liquid state and then the aluminum is forced into a mold at a very high rate. The finished product offers mechanical properties very similar to a forged wheel without the high production and tooling costs of a forged wheel. When low weight and performance are on your priority list, the SSF technology offers an excellent value. Currently only SSR (Speed Star Racing) from Japan is licensed to use this process for the production of wheels. Read more about semi-solid forging technology.

Multi-Piece Wheels

This type of wheel utilizes two or three components assembled together to produce a finished wheel. Multi-piece wheels can use many different methods of manufacturing. Centers can be cast in various methods or forged. The rim sections for 3-piece wheels are normally spun from disks of aluminum. Generally, spun rim sections offer the ability to custom-tailor wheels for special applications that would not be available otherwise. The rim sections are bolted to the center and normally a sealant is applied in or on the assembly area to seal the wheel. This type of 3-piece construction was originally developed for racing in the early 1970s and has been used on cars ever since. The 3-piece wheels are most popular in the 17" and larger diameters.

There are now many options for 2-piece wheels in the market. The 2-piece wheel design does not offer as wide a range of application that a 3-piece wheel allows, however they are more common in the market and the prices start well below the average 3-piece wheel. Some 2-piece wheels have the center bolted into a cast or cast/spun rim section and other manufacturers press centers into spun rim sections and weld the unit together. When BBS developed a new 2-piece wheel to replace the previous 3-piece street wheel, they used the special rim-rolling technology (originally developed for racing wheels) to give the rim section the weight and strength advantages similar to a forged rim. On the high-end of the 2-piece wheel market you can find wheels using forged rims and forged centers. Since these are only sold in small volume and due to the high development and production costs associated with the forging process, they tend to be on the high end of the price scale.

bigsky2
07-23-2007, 05:05 PM
The short version:

Forged - The wheel is cut out from a solid block of metal alloy.
Cast - The wheel is made by pouring alloy into a mold.

What's better?
Forged.

What's cheaper?
Cast (usually).

And as Chino said, if you can afford it, Forged is the better choice.

But don't kick yourself in the butt if you can't afford Forged wheels.

tca4
07-23-2007, 05:24 PM
I like the shorter version:biggrin:

reznunt
07-23-2007, 05:39 PM
Since no one wants to visit that Tirerack url, I'll post it.

so i'm right. thanks for verifying.

Meteorite Man
07-23-2007, 06:15 PM
Wow, How long have I been asleep? That was some read. One thing to remember with the Magnesium Rims. If you ever have a brake fire and those rims start to burn...DO NOT USE WATER!!! 6682

KAAAYEFFINBOOM!!! Makes some great sparklers too. Ever see a car with a magnesium motor burn and the fire dept gives it a good dose of water? Nasty!!!

Basically I had nothing to add but wanted chime in. All in the name of safety.

6683

Chuck

Biggie™
07-23-2007, 08:13 PM
If you ever have a brake

If seen tires catch on fire, but never brakes. :iono:

Meteorite Man
07-23-2007, 08:32 PM
Well then ya need to open them peepers just a bit more. Not an everyday thing but it does happen. When you drive 2200 miles a week on the highway you DO see things.


Just a comment to get things started? 6685 Just like the guy in the exhaust forum that sees "thousands" of Mustangs with loud exhaust getting way with it but "he" gets singled out and ticketed in his Yaris. Hmmmm....Thousands?


Chuck

slvryaris
07-23-2007, 09:30 PM
Forged but like Chino said it can cost ya some jingle.