Rivendell Ruffy Tuffy. These are rated as 700 X 27C tires (they are 29C on my bike), and made for Rivendell by Panaracer in Japan. They have a 2mm Kevlar-belt. Their Rol-y Poly tires are identical and lighter - but lack the Kevlar-belt. Both tires are fast and nimble, yet grab road and dirt equally as well.