Tubeless tyres dispense with the inner tube and can also feature a sealant liquid inside which will automatically fill and harden in the hole made by a puncture.They have many performance advantages – lighter, better resistance to pinch flats, can be run at low pressure - but because an airtight seal is required to seat them on the rim, can be tricky to install. 'Tubeless ready': Some manufacturers now offer rims and tyres that are intended to be easily converted to tubeless using a sealant kit.