Why choosing the Best Alloy Wheels is Critical *

Franza1

Supermoderator & Area Reps Manager
Reasons

There are 2 main reasons for fitting Alloy Wheels: Weight and Style. Alloy wheels are a lot lighter than the equivalent size of steel wheels, so the unsprung weight of the car is reduced. They also look 10 times smarter than a steel wheel, even with a fancy plastic trim covering it.

Looks

Looks are all down to personal preference really alot of people like 3 spoke wheels, where as alot of people also like the multi spoke design so here is no reason to go into dept about the style

Choosing the right Size
Alloy wheels are currently available in diameters from 12" to 20", and widths from 5" up to 10".

It is quite normal to alter the size of wheel when fitting alloys. Most cars are fitted with 13" or 14" steel wheels. When changing to alloys - you can replace with the same size of wheel, and keep the same size tyre, or move up to 14", 15", or even 16" or 17" wheels.

The larger the wheel and the smaller the tyre profile the more impact the wheel chosen will have on the overall look of the car. The important thing is to keep the same overall tyre diameter. This is done by using a lower profile tyre.

So if you have an Escort with 175.70.13 tyres, you can change to 175.65.14 tyres or 185.60.14, or up to 185.55.15 or 195.50.15 tyres. You can even go on to 205.45.16 or 205.40.17.

With some cars you are limited to the maximum size by the space available within the wheel arches; for instance Fiesta alternatives are 155.70.13, 185.60.13, 185.55.14 or 195.45.15

You will see that generally speaking, as we increase the tyre and wheel diameter (the last number of the size designation), we reduce the middle number (the profile percentage height) and also increase the first number (the tyre width).

The important thing is that the overall diameter of the replacement wheel and tyre combination is the same as the original fitment - so that
Gearing
Speedo reading
Acceleration
Top speed
Fuel consumption
Ride height
remain the same as intended.
I do not recommend changing the overall tyre diameter by more than ± 2½%.
Increasing the tyre width and reducing the profile height will give the vehicle different handling characteristics. The car will be a lot more responsive when cornering, but a lot more sensitive to bumps and irregularities in the road.

Performance

How it's made

Different Types of Manufacture Effects the wheels Strength as well as performance, A lot of people choose the looks of wheels without even thinking of the performance aspect of it, A lot of the performance and racing wheels tend to be more expensive then their more showy and less performance orientated cousins but It all comes down to the old Adage " You Get what you paid for"

First of all The Construction of wheels is of major importance

•One-piece Cast Wheels
A cast wheel is made by pouring molten aluminum into a mold; the metal then takes the mold's shape as it cools and hardens. There are several types of casting methods that include low pressure/gravity, counter pressure, and high counter pressure molding (HCM); each method has its place in today's market. A wheel manufacturer will select a particular method according to the weight, strength and finish that they have specified for that design. The benefit of casting wheels is the relative low cost for set up and manufacturing. However cast wheels are typically heavier and less robust compared to a wheel manufactured using a forging method.

•Forged One-piece Wheels
A forged wheel is made by forming a wheel under extreme high pressure. The material used is an aluminum billet—a solid piece of dense aluminum. A forging press, a huge machine that exerts thousands of tons of pressure on the metal, basically presses or rolls the billet into its fundamental form. This forging is then machined to final finish. This process allows wheels to be built with much less material, allowing for lighter weight and unique designs, because the process creates a much stronger wheel than other methods. Many premium wheels are made using forging technology.

•Multi-piece Wheels
The processes mentioned above can be combined to produce a wheel of a particular strength and weight. For example, some wheels have a cast aluminum center, welded to steel outer. Another type of two-piece construction features a billet center welded to a rolled outer (extruded aluminum rolled into a hoop). Still other wheels feature a split outer so that widths and offsets can be made to custom specifications. This last method is the three-piece type construction. In this type of wheel, the center that can be cast, billet or forged, is usually attached to the outer assembly by special screws or rivets.

Weight Saving

Another Crucial thing is to “Reducing Unsprung Weight” - The weight from the Suspension apparatus which includes the Tire and Wheel combination is called “Unsprung Weight”, and reducing the weight of this section is crucial to the performance of the vehicle. If 1kg of weight is saved from the suspension system, the value of a 15kg weight loss from the vehicle’s overall weight can be saved.

This means if an aluminum wheel which is 1kg lighter than a stock steel wheel is installed, 60kg of total of body weight can be saved. ”Rotating Weight” – During the driving of a vehicle, there is a pressure that is applied to the tires and wheels of the vehicle. This is called the Gyroscope effect. Especially during high performance driving conditions - acceleration, turning, and braking is all effected by these rotating forces.

Reducing weight while retaining superior strength results in success in hi-performance driving. It is now clear that a lighter wheel can positively alter a vehicles performance in many ways. The car will experience faster acceleration, better braking, improved handling, less strain on the drive-train, and even better gas mileage.

Information gathered form numerous sources
 
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