With the PAX system, the tyre wheel is made of steel or steel alloy (Michelin
Inc, 2006). The diameter of the wheel is wider than an equivalent standard wheel.
Most of the tyre designs use inflation pressure to hold the tyre to the rim, which
makes the tyre separate easily from the rim when a flat occurs at high speed.
However, the design of a PAX system wheel actually improves its grip when vertical
loads are applied to the tyre. The repairable tyre and reusable support ring can provide
a longer life for tyres. Additionally, these tyres have shorter and more flexible
sidewalls, which can reduce rolling resistance by reducing tyre roll. This also helps to
prolong the life of the tyre.
By using these unique designs, tyres can be made to last longer,
thereby reducing tyre waste (Michelin Inc, 2006). By implementing these
technologies into Hong Kong’s transportation infrastructure it may be possible to
slow the accumulation of tyre waste, though it is uncertain whether these methods
will be cost effective. Furthermore, it is unknown if these tyres will complicate
recycling or retreading procedures due to their unique design and composition.
Each material that goes into a tyre has value by itself. Steel can be melted
down, and pure rubber is easily recyclable, but the problem lies in the fact that all
these materials are strongly bound and mixed together with a mix of potent chemicals
that makes separation a difficult and costly process. For this reason tyre recycling is
not an easily profitable business (Rodriguez et al, 2001). We will outline several
recycling methods in the next section that have had varying degrees of success.