After several high-ranking results during the 2015–2016 cyclo-cross season, including a top-five result in the junior race at the 2016 UCI Cyclo-cross World Championships at Circuit Zolder, Pidcock came to prominence in the junior ranks during 2016. In September, Pidcock took a road victory, winning the :fr:La Philippe Gilbert Juniors|La Philippe Gilbert Juniors race by 21 seconds from his closest competitor. Thereafter, Pidcock concentrated on the 2016–2017 cyclo-cross season; in October, Pidcock took a victory in the Superprestige at Zonhoven, just before the UEC European Cyclo-cross Championships at Pontchâteau, France. In the race, Pidcock was able to work his way into the lead on the third of eight laps, and was able to create a gap to the rest of the field, eventually taking the gold medal by 14 seconds clear of France's Nicolas Guillemin. Thereafter in November, Pidcock was able to claim victories at the Grand Prix van Hasselt, and the BollekescrossDVV Trophy event, as well as a first podium finish in the UCI Junior Cyclo-cross World Cup, with a third in Zeven, Germany. Pidcock took his first win in the competition the following month in Namur, taking the victory around the city's citadel by almost a minute ahead of France's Antoine Benoist; he echoed previous celebrations of Peter Sagan and Mathieu van der Poel by wheelieing across the finish line. The performances had caught the eye of team manager and former world champion Sven Nys, who was looking to sign Pidcock to his team. In the run up to the 2017 UCI Cyclo-cross World Championships, Pidcock won his first British National Junior Cyclo-cross Championships title in Bradford, and won a second World Cup race in the Grand Prix Adri van der Poel at Hoogerheide, leading teammate Ben Turner home in a 1–2 finish. With his form, Pidcock entered the World Championships as one of the junior race favourites. On an icy course in Bieles, Luxembourg, Pidcock took the lead from France's Maxime Bonsergent on the second lap of the five-lap race, and held onto the lead for the remainder of the race to take the rainbow jersey, the first British junior to do so since Roger Hammond in 1992. Pidcock's teammates Dan Tulett and Ben Turner completed the top-three placings, for a British clean sweep of the podium. Such was his performance, that Belgian media referred to him as a "mini-Sagan", in reference to Peter Sagan. In May 2017, while riding for the PH Mas–Paul Milnes–Oldfield team, Pidcock became the first guesting rider to win an individual round of the Tour Series criterium competition, soloing to victory in Durham. In July he went on to win the elite race of the British National Circuit Race Championships in Sheffield, at only 17 yearsof age, attacking on the final climb on the final lap and taking the title ahead of Harry Tanfield and Jon Mould. On 19 September 2017, he won the junior time trial at the UCI Road World Championships in Norway.
Telenet–Fidea Lions
At the start of June 2017, Pidcock announced that he would join the team from October, on a two-year contract. Pidcock made his début with the team at the Polderscross Brico Cross race on 14 October 2017, where he finished as part of a five-rider group – including the likes of Laurens Sweeck and Kevin Pauwels – in ninth place, 77 seconds down on race winner Mathieu van der Poel. The following weekend, he took his first win for the team; on 21 October, he took victory in the under-23 race at the Niels Albert CX, held in Boom, as part of the Superprestige competition. Pidcock finished eight seconds clear of his closest competitor, Adam Ťoupalík. On 22 October, Pidcock again got the better of Ťoupalík in the first under-23 World Cup race of the season, at Koksijde. In November, Pidcock took the silver medal in the under-23 race at the European Championships, in Tábor, Czech Republic; Belgium's Eli Iserbyt out-sprinted him to the finish line in a two-up sprint but Pidcock raised his arm in protest, claiming that Iserbyt had made an irregular sprint, boxing him in at the barriers. In December, it was announced that Pidcock would ride for in road races in 2018. On 26 December 2017, Pidcock won his fourth World Cup race in as many starts, at the Grand Prix Erik De Vlaeminck held at Circuit Zolder. With the victory, it gave him an unassailable lead in the World Cup standings, as a rider's best four scores count towards the classification. In the run up to the 2018 UCI Cyclo-cross World Championships, Pidcock won his first British National Under-23 Cyclo-cross Championships title in Hetton-le-Hole, winning the race by over a minute from his next closest competitor.
