Smart composite puncture-proof and flat-free tyres

Tyres represent the biggest repair problems and operational costs for wheelchair users,
cyclists and public bicycle sharing scheme (BSS) operators globally and a tyre puncture can
present significant problems for wheelchair users and commuter cyclists. Traditional
pneumatic tyres comprising an air-filled inner tube and a rubber outer shell are the preferred
choice, offering the best ride performance, shock-absorbance & traction, despite the risk of
punctures & air leakage. Under inflated pneumatic tyres suffer reduced performance, greater
wear & degradation, sidewall cracking & eventual tyre failure posing a safety risk &
increasing maintenance costs further. Advanced rubber pneumatics can be manufactured with
a puncture resistant infill, however, this is expensive (standard tyre >£20) & air leakage
remains a problem.
Non-pneumatic microcellular polyurethane tyres are a puncture-proof alternative and are used
for wheelchairs & bicycles, offering reassurance against punctures but have a hard ride, poor
shock absorbance, greater rolling resistance, lack of rebound, reduced traction, & wheels must
be checked and maintained more frequently due to deterioration of spoke tension. Compared
to pneumatics, polyurethane tyres also have slightly less grip than pneumatic tyres, which can
be a problem for secure braking, especially for self-propelled wheelchairs.
Greentyre Limited, the original developer of puncture proof polyurethane tyres, seek to
develop an advanced flat-free tyre using a novel micro-cellular PU & rubber composite that
can provide equivalent performance to a rubber pneumatic, at lower cost, with longer life &
reduced weight, significantly reducing the current performance gap between airless &
pneumatic tyres to meet demand in the wheelchair & commuter bicycle/BSS markets. The
project focuses on the development of a novel tyre production processes and prototype tyres
for wheelchair user and cyclist trials.