IRC RS-310 Durotour Rear Tire (110/90-17) IRC aspires to provide rides with high performance tires for any condition. Their mission is simple: To provide superior and never-ending product development and customer service. Their goal is to be your number one tire partner.IRC&#39;s hottest selling products for years.For general all around performance, handling, and mileage, nothing beats a pair of RS-310&#39;s.Original equipment on the Honda CB400SS.Sold individually.Tire Sp Construction: Tubeless. Overall diameter (mm): 634.