According to the International Rubber Study Group, world output of rubber increased around 10% in 2010 at 24.3 million tones. Synthetic rubber and Natural Rubber was 55% and 45% respectively. 
Supply and Demand may only be part of the story for current rubber prices according to a recent report by ANRPC (the 11-nation association of Natural Rubber Exporting Countries that make up 92% of natural rubber output). Their recent report has noted four factors that can keep natural prices high during the short term.
Short Term
Long Term
Commonly referred to as foam fill, tire fill, and poly fill, Arnco’s patented products reduce downtime related to punctured tires or flat tires. The liquid polyurethane is pumped into the tire through the valve stem until it replaces all of the air which now results into a solid tire, but with a softer ride than a solid rubber tire. The result are flatproof tires that improve the productivity of the equipment
Rule #1 – remember to park your truck away from large haul trucks!
Instead of going to the gym today, maybe it’s time clean up that old inventory!
With almost all tire prices continuing to increase, demand is simply not keeping up with supply as some large mining tires have already passed the $100,000 per piece on the spot market (see article here). 
The solution? Polyurethane Tire Fill will extend tire life, increase productivity and reduce the cost of tire repair or replacement.
See here for what mining equipment can be tire flatproofed:
Commonly referred to as foam fill, tire fill, and poly fill, Arnco’s patented products reduce downtime related to punctured tires or flat tires. The liquid polyurethane is pumped into the tire through the valve stem until it replaces all of the air which now results into a solid tire, but with a softer ride than a solid rubber tire. The result are flatproof tires that improve the productivity of the equipment.