[jyl]

Complicated. A little after Mercxx set his record, people started using aero bikes, disc wheels, aero positions, etc. UCI created two types of hour record, the "Athlete's Hour" required using an old-school track bike like Mercxx rode, the "Best Human Effort" allowed most aero technology but still disallowed some positions. Indurain did a best human effort ride. In 2014 the UCI changed the rules to have just one official hour record, allowing equipment legal for track pursuit racing which permits much but not all aero technology. Jens took the opportunity to set the first record under the new hour record rules. For sure his record will fall when the time trial specialists like Martin, Wiggins, etc make their attempts. But it was a perfect opportunistic move, much like the breakaways that are his signature.