Onza xiii mtb tyreroger rinderknecht is the xiiis father no wonder this tire has what it takes the well balanced pattern makes it the weapon of choice for every race track roger showed at the olympic games of peking how well this tire works continue the success story of the xiii yourself features size 26 x 225 etrto 57 559 casing r xiii tpi 60 bead steelwire rubber rc2 durometer 65a55a weight 760gbuy onza tyres from chain reaction cycles the worlds largest online bike store