E thirteen trs mtb tyresfrom the ground to the rim e thirteens trs mtb tyres are engineered to give the grip you need at race speeda row of hard biting side knobs is bolstered by an angled structural base to control roll under high speed cornering sipes on the knob surfaces are positioned to provide confidence while transitioning from straight line to cornering and back and underpin excellent braking traction ramped shorter centre knobs keep trs tyres rolling fast the fanciest knobs in