Seat tube measures 634mm (c to top) and is 28.6mm diameter Columbus Zona tubing with wall thicknesses of .8/.6mm.. Top tube measures 610mm (c to c) and is 28.6mm Columbus Life tubing with wall thicknesses of .75/.45/.75mm. Down tube is 31.75mm diameter Columbus Life tubing with wall thicknesses of .5/.7/.5. 650b x 42mm tires.