| Aluminium alloy wheels are made from a mixture of aluminium and silicon: blended to exact proportions for maximum strength. The foundries have a spectrometer to test for the exact composition before casting the wheels.Aluminium is a very reactive metal which easily corrodes (to aluminium oxide, a white powder) if not protected from air and water.Most alloy wheels are made by casting in a mould to produce a complete wheel, but some are made in 2 pieces - the rim edge and the spokes are then bolted together, and some are made in 3 pieces - the centre spokes, the front of the rim, and the back of the rim. This means wheels can be made more easily in different widths to fit wider tyres: mostly applicable to racing requirements but also for high performance cars where it is not economic to make a mould for a just a few wide wheels.It is also possible to machine alloy wheels from a single billet of alloy for low volume requirements where mass production techniques are not viable.There are 2 main reasons for fitting Alloy Wheels: Weight and Style. Alloy wheels are lighter than the equivalent size of steel wheel, 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.Using modern alloy casting techniques it is possible to create quite exotic shapes and styles of wheel, whilst still retaining adequate strength.Originally alloy wheels were produced with a polished finish and no paint to protect the alloy from corrosion. Then it became normal to supply alloy wheels with a silver painted finish, and in some variations with a diamond polished rim edge protected by lacquer. Advancing from this some highly reflective paint finishes were used to replicate the original polished finish.The design of the latest styles of alloy wheels includes spokes with a twist or bend in them, spokes on 2 layers with the inner layer black and the outer layer polished, and coloured inserts in the spokes.Current alloy wheel styles have moved on to include all black finishes, highly polished stainless steel rim edges, coloured red or blue or yellow bands around the rim edges, and various other combinations.The style of alloy wheel to choose is actually the most difficult decision to make. So much depends on your personal choice: though it is also related to the other factors such as size of the wheels and available vehicle fitments, and of course cost.A lot of cars are now fitted with alloy wheels as standard but many people choose to replace them either through personal choice or to fit bigger diameter wheels with a lower profile tyre. The reason for doing this is to improve the cars handling - a tyre with a smaller sidewall will flex less when cornering so improving the feedback through the steering wheel: and of course a bigger alloy wheel looks more impressive.Many of the lower price alloy wheels are now made in the Far East where production costs are lower. This does not mean they are inferior quality: many of the major UK names such as Wolfrace and Momo have their alloy wheels manufactured abroad to the same standards as European made wheels.There are a range of different vehicle fitments in use: the number of fixing bolts or studs varies from 3 to 6, the distance between the studs varies, and the diameter of the centre bore in the wheel varies between different makes of cars, and the offset of the wheel: which is the amount by which the wheel fits into the wheel arch relative to the vehicle hub must be correct for the car.Most after-market alloy wheels can be supplied in these different fitments but it is essential that the car make, model, version and year are correctly specified when ordering. You should also check that a wheel fits correctly on the hub before fitting any tyres, and that you have the correct bolts or� nuts to secure the wheel. After fitting new alloys, recheck the torque of the fixings after about 100 miles of driving.� Find out more at http://www.tyresave.co.uk |