Nu-Tek 700 x 35 Hybrid Airless Solid Black Bicycle Tire w/Street Tread. Nu-Tek 700 x 35 Hybrid Airless Solid Black Bicycle Tire w/Street Tread. Guaranteed never to go flat!! Maintenance free - no need for inner tubes, air pumps and puncture (repair) kits. High resistance to wear and tear. Laboratory tests have shown expected life span two to four times longer than a rubber tire. Weight - equal to or less than pneumatic tire and tube. Nu-Teck tires are manufactured in the USA which is unique since United States production of bicycle tires was totally discontinued in 1987.