The start of the 2015 Tour de France has been action-packed for team mechanics, with a time trial and cobbled stage crammed into the first four days.

That’s meant that each rider needs, at the least, two time trial bikes (one main bike and one spare), and two cobbles bikes alongside their regular race machines, significantly upping the already strected workload of the world’s best mechanics.

The pavé of stage four will place a particular focus on each rider’s equipment, with 13.3km of bone-shaking cobblestones, divided in seven sections, to feature on the 223.5km route from Seraing in Belgium, to Cambrai in France.

Those pavé secteurs may make up just six per cent of the stage, but the cobbles are so harsh, and could play such a significant role in the outcome of the race, that standard equipment is discarded, and replaced by specialist frames, fat tyres, and other modifications designed to tame the cobblestones.

Let’s take a closer look at some of the cobbles tech used for stage four of the 2015 Tour de France.