The initial Tyre Lock Prototype
Once a conventional car or truck tyre has been depleted of tread it is put aside, waiting to be thrown into a landfill, or burnt. In the United States alone, it is estimated that 2 to 3 billion tyres are stockpiled in abandoned or illegal piles.
Tyres are incredibly difficult to recycle due to their very complex composition. An average tyre will be composed of approximately five different materials. These are embedded in each other, making separation incredibly work intensive and in some cases, impossible.
The composition of a automotive tyre (Info House (1971) Tire Components)
Material and Process:
However, most of the composite material inside a tyre is contained inside the sidewall and bead; the steel and kevlar reinforced strip of rubber that hugs the inside of the rim, preventing the tire from ballooning and ejecting when at speed.
This poses an interesting recycling issue. The idea that has been realised removes the sidewall, and uses its already existing properties to their full extent. The removal of the sidewall allows the remainder of the tyre to be processed as a building feedstock; it can be added to concrete and asphalt to create a slightly softer more ‘springy’ surface.
Cutting the sidewall of the tire. The strands of nylon running sideways under the tread can be seen
One considerably more dull Stanley knife and removed tyre sidewall later
The locking ring created from this process is incredibly strong, as it is already reinforced with kevlar beads, with a series of tempered steel cables running inside the sidewall. This composition of many different materials makes the lock hard to cut with a single tool. A sharp knife cannot be used to sever the steel cables, and the rubber clogs the teeth of a hacksaw blade or an angle grinder,. As an added bonus (in an ideal world), if the lock was cut in this way, the rubber would give off a terrible smell, alerting those nearby to the crime being committed.
Through both prototype development and brainstorming the weak points of the lock have been realised, and two steel components have been fabricated to strengthen the integrity of the lock. These prevent a potential thief from cutting through the unprotected side of the bead, and pulling the padlock and rivet out.
The rubber surface of the tyre means that the lock will not scratch any bicycle components that it may be securing, and also prevents the lock from being susceptible to ‘freeze shattering’
There is a huge supply of used tyres available. Garages are very willing to give worn tyres, as currently they have to pay for their disposal. The process could also be a consumer lead initiative, whereby dropping off your old tires you are entitled to a free lock.
The lock and all components could be manufactured with a few basic tools and a jig that allows the bead of the tire to be cut neatly. The costs of the materials needed are next to nothing. I feel that although the product has its pitfalls, it’s ultimately an interesting and realistic concept that could unlock the untapped potential of a waste product.
A series of vector graphics depicting how the process could work
A prototype of the Tyre Lock in action
A few rudimentary tests of the locks durability against different tools were carried out. A video of these is shown below, including the fastest hacksaw cut time (on one tyre sidewall it took more than 4 minutes and forty seconds to sever completely!)
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