720531Smart composite puncture-proof and flat-free tyresClosedGRD Development of PrototypeInnovate UKTyres 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.