For a Grand Tour debutant, the midpoint of the race can be the most daunting of all. By the second week, he has already raced for longer than ever before, but he must cover the same distance again just to make it to the finish. After wading this far into the deep end, it's a case of sink or swim.
"The level is quite high here but I think at the moment my body is coping quite well," he said. "The harder stages are coming and I'm looking forward to them, which is a good sign."
Those words were prescient. Stage 12 of the Giro saw the race enter the mountains for the first time, and Dunbar showcased his abilities as a climber and his powers of endurance by placing third on a stage won by Cesare Benedetti (Bora-Hansgrohe) in a five-up sprint.
"I'm a bit disappointed really," Dunbar said after rolling to a halt past the finish line in Pinerolo. "I felt like I was one of the strongest there. I knew I wasn't the quickest, but I was certainly one of the strongest."
The Corkman had set out from Cuneo seeking to grab any opportunity that arose. He was swiftly aboard the break of 25 riders that forged clear after 15km and he proceeded to attack on the first category 1 climb of the race, the Montoso.
That acceleration helped to reduce an unwieldy break to a smaller and more dynamic group over the other side, and Dunbar was one of just seven riders still in contention for stage victory on the final approach to Pinerolo, which featured the short and steep ascent of San Maurizio with a little under 2km to go. Dunbar followed his own tempo when Gianluca Brambilla (Trek-Segafredo) and Eros Capecchi (Deceuninck-QuickStep) accelerated on the steepest section before catching the Italian pair on the drop into Pinerolo.
"I didn't feel super, so I just worried about what gear I'd pick," Dunbar said. "I thought if I started at the back, I'd see who was strong. Normally when guys are feeling it a bit on a climb like that, they ease back quickly. So I waited and kind of took in who was strong. I knew if I got across to the top two there was a chance."
The 22-year-old may well have had the measure of Brambilla and Capecchi in the event of a three-up sprint, but his task became rather more complicated when they were joined by chasers Benedetti and Damiano Caruso (Bahrain-Merida) within sight of the line. Brambilla led out a sprint where all concerned were running on fumes.
"I just gambled at the finish," Dunbar said. "I had Brambilla and Eros there. I knew being Italian they were going to be a bit more keen than me to get to the finish, so I gambled on that and I got caught by the guys behind. But that's bike racing. You live and learn, I suppose.
"[The sprint] was just literally who could push the biggest gear, and I think the other guys probably have that experience on me and that extra bit of endurance, but it's a start for sure for me."
Originally slated to ride the Tour of California this month, Dunbar was drafted into the Ineos line-up for the Giro at a week's notice when Egan Bernal was forced out after breaking his collarbone in a training crash. Dunbar was at the Tour de Yorkshire when he learned of Bernal's crash, and within hours he was informed that his services were required in Italy rather than the United States. He marked the news with a pugnacious display on the following day's final stage in Yorkshire.
"After the Saturday stage in Yorkshire, we were told Bernal had broken his collarbone, and then within two hours of that I was told I was riding the Giro. It was a nice surprise and it probably gave me a lot of motivation for the day after," Dunbar said.
"It was always mentioned that if something did happen to someone I would be in the mix for the Giro, but when it's so close to the race, you don't really think about it, so I was focused on California. But I was planning to go there in good condition, so it was basically no different to come here and race."
Dunbar, who now lies 28th overall, 10:11 behind new *maglia rosa Jan Polanc (UAE Team Emirates), is part of a youthful Ineos line-up at this Giro, alongside Pavel Sivakov, Tao Geoghegan Hart and Ivan Sosa. The squad was initially built around Bernal, but Sivakov and Geoghegan Hart were handed the freedom to ride for the GC in the Colombian's absence.
Sivakov impressed on Thursday, finishing with Primoz Roglic (Jumbo-Visma), Vincenzo Nibali (Bahrain-Merida) and Mitchelton-Scott's Simon Yates in the group of favourites, and the Russian currently lies 19th overall.
"Pavel and Tao are going for the GC, but it's a learning curve for them as well," Dunbar said. "We're not looking to win the Giro d'Italia, but we're looking to be seen. And I think you'll see a lot of us in the next few days."