The datum 20 marks a turning point in road riding the end of our unhealthy love affair with the 23c tyrepeople are coming round to the fact that maybe what the pros are using perhaps isnt quite the right choice for them its this ethos genesis have tried to emulate with the datum 20 distinctly traditional elements brought bang up to date with the pairing of rs505 hydraullic disc brakes shimano 105 mix groupset a responsive durable modern carbon fiber frame and fast rolling clement str