Tech Focus | OXiTECH, the new AMV magnesium rims

Back

Exclusive Content

Tech Focus

OXiTECH, THE NEW AMV MAGNESIUM RIMS.

Max Bernardi

10 July 2019

Performance and durability. These are the characteristics that all enthusiasts look for in a magnesium rim for karts. The specialized company AMV (Alluminio Magnesio Veneto) has summarized them in a unique, futuristic product, the OXiTECH rims. Let’s discover them

Rims are very important accessories whose shapes and materials modify the kart’s setup and greatly influence the tires temperature and performance both in terms of lap times and their overall durability. AMV, a company with an unparalleled wealth of competency and experience in the industry has designed new magnesium rims which utilize the advantages of low-pressure castings and the new OXiTECH treatment which improves the quality level of the product, its performance and durability.

AMV

AMV, based in the north-east of Italy, in an area greatly interested and involved in karting, was founded in 1992 as a kart rim manufacturer. In 2008 the company was taken over by the Stefanello family who expanded the production to other magnesium components for karts such as gearwheel supports, disc housings, hubs and complete braking systems. Presently, the manufacturing of these products for third party vendors constitutes its main activity. Over the years, AMV has always distinguished itself for its dedicated and consistent work on research which recently culminated in the development of low-pressure casting and OXiTECH treatment. Two processes that allow the manufacturing of high-quality magnesium components for karts while representing a new step into the future.

THE OXiTECH PROJECT

As Tommaso Stefanello, owner of AMV explains the OXiTECH rim was born from a specific need: “The magnesium rim, after the mechanical machining presents an issue linked to its oxidation. This natural process is usually limited by the use of a chromate conversion coating, a magnesium corrosion inhibitor with an iridescent gold yellow color that is somewhat obsolete. The main limitation is its duration as, with the passing of time and the use of the rims, the coating is lost leaving access to the oxidation and corrosion of the magnesium. Hence the desire to study an alternative method that would allow us to maintain the aesthetic and functional properties of the magnesium rim unaltered throughout its existence”.

TREATMENT

The innovative OXiTECH treatment introduced by AMV consists of a special plasma electrolytic oxidation which gives the magnesium extraordinary characteristics of protection from corrosion and wear. Unlike traditional anodizing treatments, the new process uses electrostatic discharges which create a plasma like substance on the surface of the piece, thus obtaining a micro-fusion of the oxide layer which mineralizes and compacts, increasing hardness and resistance to wear. The coating is about 10µm, a minimum measure which does not influence AMV quality parameters and allows, unlike painting, the rims to not have to go back to machining centers to correct the impacted surfaces.

THE CASTING

The OXiTECH treatment is the last step in the production of a rim. First, AMV products can count on another state-of-the-art process which utilizes the low controlled pressure to raise the quality of the casting. The key element of low pressure casting is to ensure a very reduced porosity that does not require the surface to be painted, otherwise necessary to fill the micro holes given by the porosity and avoid air leaks. The advantage is not so much to eliminate a step in production, as to eliminate the problems associated with that step. Painting, in fact, creates an insulating layer which degrades the thermal exchange properties of magnesium, thus damaging the rim’s performance.

Two magnesium rims ready for C.N.C. machining

The two machines from which the rims come out: on the left in aluminum, on the right in magnesium

Raw casting

Magnesium

OXiTECH, TWO VERSIONS

There are two types of new AMV magnesium rims with plasma electrolytic oxidation treatment. The Tiger model has longer spokes and an inner offset which gives more rigidity to the rim, thus being suitable for the more powerful Shifter category. Furthermore, the Tiger rim increases grip, a useful feature when exiting a turn. For the non-shifter category AMV has designed and manufactured the Flangia Piana model which, unlike the Tiger, has no spokes but a full and flat shape in the hubs contact area. Thanks to their design, the Flangia Piana rims give the kart a “softer” driving feel, an advantage to the kart’s smoothness. Both versions have the same section designed to have as little air as possible inside the rim.

On the right the “Tiger” rims, on the left the “Flangia Piana” model

A detail of the “Tiger” rim’s spokes, useful to make the rim’s structure rigid

THE BENEFITS FOR THE KART DRIVER

The new OXiTECH rims, both in the Tiger and Flangia Piana version, are matte white. This is a shade given by the compact layer of ceramic oxides derived from the plasma electrolytic oxidation process which may not seem very suitable for a racing vehicle like the of a kart. Reality, however, proves just the opposite as the OXiTECH treatment improves the cleanliness of the rim and eliminates the possibility for the magnesium to absorb dirt and for stains to not remain. Furthermore, the layer generated by the plasma electrolytic oxidation process acts as a protection and the rim, even after several tire exchange operations, unlike chromate conversion and painting, does not show any abrasions, looking as if it was just purchased.

ENVIRONMENT

Despite being the last point of this article, attention to the environment is one of the main factors behind all of AMV Research & Development. As said, the new OXiTECH treatment implemented by the Italian company eliminates the chromate conversion process used before. A process which involved the use of chromium-6, which is extremely harmful to the environment. The OXiTECH treatment, on the other hand, does not use toxic chemical substances or hexavalent chromium and has virtually no impact on the environment and the overall health.