Alloy is a mixture of metal with another metal of more value for more superb quality and durability, and this is what composed the Alloy wheels. They are wheels intended for automobiles (like trucks, cars and motorcycles) which are made from magnesium or an alloy of aluminum.
These are much lighter for the same strength and noted to provide superb heat conduction. They have enhanced appearance to look grand and classy.
The first known Alloy Wheels were made of magnesium, but they were not so favored by common vehicles because they were not too safe to use. In spite of this, they also gained popularity although in limited numbers only. In the mid year of 1960 and onwards, manufacturers have refined a safer Alloy Wheel utilizing aluminum casting but they were also proven quite brittle, and have suffered low ductility (2-3% elongation). As technology keeps improving, wheel manufacturers have enhanced aluminum casting of these light alloy wheels, and at the same time made reachable for the common automobile users.
At present time, Alloy wheels are making waves in the market as a cost-effective choice for wheels with its improved features and high performance value.
- Improved handling
- Improved grip
- Allows suspension to focus more on the terrain
- Reduction in overall mass of the vehicle (because the wheels are lighter)
- Fuel consumption minimized (due to reduced mass)
- Better heat conduction dispels heat from the brake
- Improved brake performance
- Overheating minimized because of minimal chances of brake failure
Magnesium Alloy Wheels: Methods of Production
Mag wheels are the common term for Magnesium Alloy wheels. They are at times used on racing cars to replace the use of heavier steel or Aluminum alloy wheel, for an improved performance. Mag wheels can be produced in variety of means.
Forging is a method to produce mag wheels. It involves one or multitude of step forging processes from a variety of magnesium alloys like ZK60 (in Russian, MA14) and AZ80. It is proven that wheels are of higher stiffness and ductility when produced through forging (than that of the aluminum wheels) but it demands a higher price.
HPDC (High-pressure die casting) is another method of producing magnesium alloy wheel. In this process, a die is arranged on a large machine that is capable of a high-closing force to fasten the die closed. There is a filler tube (otherwise known as the shot sleeve) where the molten magnesium is poured. When a high-speed piston pushes the metal with high pressure into the die, the magnesium got solidified and the die opens up to let go off the wheel. Wheels produced through this method are often less ductile and lower in strength and corrosion resistance primarily due to the nature of this method itself, this is why they are sold in a much lower price.
LPDC (Low -pressure die casting) is another method of making mag wheels that utilizes a steel die. It is arranged on top of the crucible (a vessel made of refractory material used for melting a substance through a high degree of heat) filled with molten magnesium. In most cases, the crucible is sealed next to the die and with the use of pressurized air it forces the molten metal to rise up through a straw-like filler tube into the die. This process is so far, the best method because it offers improved ductility and strength than those Magnesium Alloy wheels produced through forging or through high-pressure die casting means.
Gravity casting (sand casting and permanent mold) method of making mag wheels have long been in existence since 1920. This method produces good quality of wheels above all wheels produced with aluminum casting, and is proven of better ductility. Tools and materials are cost-effective; the designs have variations to choose from, and most of all this can be produced in a shorter period of time. This offers more opportunities for small-batch production.
Advantages of Alloy wheels
People consider buying alloy wheels due to pure aesthetic reasons. The fact that it changes the appearance and resale value of a vehicle impress any automobile owner. What is barely realized is that there are numerous technical reasons why fitting alloy wheels to your automobiles are advantageous too. Almost all brand new vehicles come fitted with standard wheels which are made of steel because they are a lot cheaper, although manufacturers can offer mag wheels as an additional upgrade.
Alloy Wheels are more costly to produce than its counterpart steel wheels, and are not often included if you purchase a brand new automobile. It can be marketed as an optional accessory, an add-on so it states. An expensive car package bears a set of mag wheels, the standard package comprised only the wheels made of steel. However, in early 2000 up to the present time, automobile industries have begun to revolutionize manufacturing of subcompact and economy cars with mag wheels to enjoy its rightful place in the competitive car market.
An option to add mag wheels presumably adds up to the cost of the brand new vehicle. Vehicle owners opt to buy Alloy Wheels for the following reasons: -
- Unsprung Weight – is the total weight of everything attached to the wheels (wheels, tires, brakes, bearings, spindles and some of the weights of the spring, suspension links and shafts). Because alloy wheels are lighter, unsprung weight is reduced. It is just important to maintain a low unsprung weight in order to have optimum contact with the surface of the road. If it’s too high, the reaction of the suspension is slowed down due to build up of inertia through the wheel’s weight. Improved traction is maintained because the suspension can readily react to many road surface’s imperfection because of reduced sprung weight.
- Tire Options – by fitting Alloy wheels to your automobiles, you have an option to fit wider tires or tires having a lower profile. These types of tires improve steering tremendously. Steering becomes more responsive, and when in the point of cornering there is lesser chance to distort the camber. It lowers the rolling resistance which helps in acceleration. Side walls become more stable when braking, and you can possibly allow fitting of larger brakes. On top of it, lesser fuel consumption.
- Some Other Weight Issues – it is important that you should always remember that the wheels are moving parts capable of building up inertia, so its weight is just so important than the stationary parts (like the axle). The heavier the wheels are, the more energy the vehicle needs to speed up or slow down the run. If you choose to fit Alloy wheels in your automobiles, you will notice that the amount of required energy is almost reduced compared to the standard wheels made of steel. As the overall weight of the vehicle becomes lighter, you will notice favorable repercussions in your car’s performance such as braking, acceleration and fuel consumption.
- Brake Performance – is dependent on the reduced weight of the vehicle and the wheels, but the weight is not just the one helping the brake to perform better. Alloy Wheels aid to dissipate heat buildup caused by the brakes than their steel counterparts because of the differences of materials they were made of. There are also additional slots on alloy wheels that allow more air flow over greater surface area. This contributes to lesser chances of brake failure; instead your brake is expected to deliver a good performance for a long time. Because of this, the life expectancy of your vehicle is prolonged while it is preserved to function well on the road.
Disadvantages of Alloy Wheels
Every coin has two sides, just as Alloy wheels have great advantages, they also have some down sides and these must not be overlooked. These wheels are high in maintenance, simply means they have to be washed often to maintain the glossy finish. Apply caution in the type of chemicals you will use to clean the wheels, others can just be harsh and may damage its finish.
Another con is that you may find less riding comfort if you are running with a lower profile tires. It is important to be careful when parking along the side of the road to avoid scratches from the gutter or from hitting the curb. Because of negligence you might invalidate the warranty if your car is just newly acquired.
These wheels are purchased primarily for aesthetic purposes, but you should also know that the alloys employed are hardly corrosion-resistant. Alloy allows the use of pleasant bare-metal finishes, but this necessitates to be further sealed with wheel covers or paint. Even though how much you protect them, they will also corrode in a matter of 3-5 yrs. Refurbishment is an available remedy at an additional cost. Alloy Wheels manufacturing is now of intricate and bolder in designs. On the contrary, steel wheels are just pressed sheet of metal welded together and often leaving bumps that are not good to look at. They must be yet painted to prevent from corroding, or can also be hidden with hub cabs (wheel covers).
Alloy Wheels are most likely prone to cases of galvanic corrosion. This causes tires to leakage if not well-taken care of. These types of wheels are also difficult to repair when bent than its steel counterpart. Of course, high cost of repair is a good alternative rather than buying a new one which is way much expensive.
Alloy wheels continue to evolve changes through passage of time. For some people, it is pure styling but with lesser functions. As modification keeps improving the face of mag wheels, prices go up too; this is why a lot of people consider this as status symbol. These wheels now come in varieties of sizes, shapes and even colours. The lower the profile of the type and larger the wheel, the better it looks. Large wheels have adverse effects on handling. They can even rub on the arches of the wheels on full lock. Tuning the car is always recommended.
Some customers even stated some reasonable points of limitation in fitting mag wheels compared to standard wheels. For them, a lot were discussed about aesthetic value of mag wheels when in fact roadworthiness should be the point of consideration. Cars do have numbers of nuts on its hubs wherein the sizes and distances of these nuts also vary, plus the internal spaces in the wheels for brake discs likewise comes into play. Be careful in knowing the measurement of your standard wheel, PCD and offset likewise and make sure your new ones can tolerate this.
Points To Remember:
On rough-textured alloy wheels brake dusts tend to cause pitting. This is why complicated wheel patterns can really make cleaning a major problem. The best solution is to mat a new Alloy to low-brake dust pads. A good switch to low-brake dust pads contributes to simple rim maintenance. Cleaning the spinners is a bit complex too but all the more makes spinning a lot more interesting as compared to the rest of the wheels. When you opt for mag wheels in your vehicles, ask for the balancing weights to be fitted to the inside to get rid of its unsightly look.
Many alloy wheels displays a better view of calipers and brake disc, be sure that these parts are in best conditions, a bit of caliper paint may do the trick. A wide selection of stylish looks are also possible like chrome alloys against dark-painted work, considered as VIP style. For a sleeper look, spray them dark. Kerbed alloys is never good-looking this is why a well-selected tire should include wide wall to avoid the unsightly scrapes. Some alloy wheels can be seen with some designs sticking out so kerbing is requested.
Spacers found inside the wheel (against the hub) may result to the tyres lining up on the edge of the arches; such widening can improve car’s handling. Split-rims having two parts have multiples of connecting bolts, this will also cause the wheel to fill the arch; thereby can allow the use of a wider tyre. Always bear in mind that when the wheel is wider (or bigger) than the standard, the suspension set up needs to be realigned to not compromise the handling, and most of all safety.
Gone are the days when alloy wheels are for luxury cars and sports cars only. The expensive alloy wheels are most likely to attract carnappers and carjackers, to counteract this, a wide number of automakers provide the usage of a locking wheel nuts (with a special key) to ensure protection against thieves.
In summary, there are so many technical reasons attributed from the use of Alloy wheels other than pure aesthetics. Although it requires additional cost to invest for the set of wheels, in the long run, you will notice a great advantage especially on fuel conservation and brake’s life expectancy. Being realistic enough, the point of fitting alloy wheels into your car is obviously to show off, that is how the usual mentality runs. You are most likely to enjoy seeing your car cool than buying yourself a new pair of shoes.