Finishing eighth in the omnium — a two-day, six-event track cycling challenge — had taken its toll on the Canadian rider, who came to London with a stacked resume and high hopes.
"It's been a hard two days, no doubt about it," said Bell. "More mentally than anything.
"I've missed the podium twice in this event in my life: here and one world championship. That's it. To have two bad days now is hard. It's similar to what (heptathlete) Jessica Zelinka went through. She came here with the same kind of aspirations. My heart went out to her, I know her a little bit and I kind of felt like we were in a bit of the same situation, we both had a really good shot.
"There's great stories from lot of our teammates in Team Canada and then there's the ones that things don't go our way. And we're a couple of those. That's just how it is."
Bell, a silver medallist at the world championships earlier this year, found himself behind the eight-ball after a disastrous first day Saturday left him in ninth place overall.
He was seventh in the 250-metre flying lap, 13th in the points race and 10th in the elimination race.
On Sunday, he was eighth in the individual pursuit, first in the 15-kilometre scratch race and 10th in the one-kilometre time trial.
In comparison at the worlds in April, he was fifth in the flying lap, third in the points race, eighth in the elimination race, second in the individual pursuit, second in the scratch race and eighth in the time trial.
Bell finished the world championships with 28 points after six events. He had 30 points after three events here and finished with 49 (in the omnium, the fewer the total points the better).
Also Sunday, Calgary's Monique Sullivan finished 11th in the women's sprint after a busy day that saw her take part in two repechage races.
She made a point in her post-race interview to sent a shoutout to Bell.
"Today was heartbreak for Zach, but he's come so far," said Sullivan. "And the omnium is really a tough event to get right."
Edmonton's Tara Whitten, who helped Canada to a bronze in the team pursuit Saturday, takes to the track again Monday for the start of the women's omnium. She is a favourite to win another medal — not a bad payoff for a small team with limited resources and which has to go to Los Angeles to train on a 250-metre track.
Coach Richard Wooles acknowledged the team had pushed Bell "as hard we possibly could" in the leadup and perhaps erred on the timing.
"And I think with hindsight we were probably a week or so out. We really went for it as much as we could. If he wasn't on the top of his game, he wasn't going to get a medal. And I think we put everything into this to try to get him better than he's ever been ... We went to the max. And I would just say he was just either a little bit stale or we just went slightly over.
"You could see by today he was pinging. .... But the guy's got a massive reserve and to show what he did tonight, he's an awesome athlete and an awesome competitor."
Wooles, a veteran coach who is originally from Wales, added "with the resources that we had, we did a great job.
"But I think if we can build a program in the future and get more people involved, maybe we won't make these little mistakes."
Wooles was a volunteer coach with the Canadian team. Now he is a paid coach and the team is gradually building a framework.
Bell, a 29-year-old from North Vancouver who grew up in Watson Lake, Yukon, some 400 kilometres east of Whitehorse, is a former World Cup champion in the omnium. He placed seventh in the points race at the 2008 Games in Beijing.
Bell said his pre-Games training had gone well. He expected big things.
"But you know it's the Olympics. And if everything isn't right on perfect point, you lose a little bit," he said. "Most of the events were on par, just slightly slight subpar. I lost a lot in that points race. With the other guys going the way they were, there's just no coming back from that."
Denmark's Lasse Norman Hansen, bronze medallist at the worlds, won gold with a total of 27 points. As he took his victory lap, the Danish flag trailing him, the baby-faced 20-year-old wore the scars of a crash in the scratch race. His tunic was torn and his knee skinned.
Bryan Coquard of France took the silver and Britain's Ed Clancy collected the bronze.
The winner in each event gets one point, the runner-up two points and so on, with the overall winner being the rider with the least total points.
Bell made his statement in the scratch race, putting on a late burst to take the lead, holding off Spain's Eloy Teruel Rovira. Bell punched his fist in the air in celebration as he rounded the turn after the finish.
Bell is one of the best scratch racers around. Wooles encouraged him to take ownership of this one.
"I won a race at the Olympics," said Bell. "I mean it's not the whole thing but it's one event and that's a lot more than most of the guys here can say."
Bell suggested the scratch race win was a form of payback to all those who encouraged him to pick himself up. And he wanted to give kids in the Yukon something to cheer about.
As far as his future is concerned, there are still some races his Team Spidertech schedule. Plus wife Rebecca is seven months pregnant.
"I've probably got to paint a room or something in the future," he said with a smile.
As for the 2016 Olympics, he said "there's one and a half people in the crowd who are going to have to answer that question before I do.
"It's not totally off the radar but it's still a ways away from that discussion."
Sullivan showed resolve and plenty of promise before heading to a race for ninth through 12th place after exiting in the 1/8 finals repechage where she just failed to run down Olga Panarina. The Belarusian had posted the fifth fastest time in qualifying.
"A fabulous result," said Wooles. "For the whole competition, she raced about her level. She really raised her game ... She's a real star for the future."
In the preceding 1/8 finals, Sullivan was handily closed out by Australian Anna Meares, a silver medallist four years ago in Beijing.
The young Canadian made it to the 1/8 finals via the repechage route. Sullivan, who was 12th in qualifying in 11.347 seconds, took the lead in the final lap and held off Hyejin Lee of South Korea to qualify for the next round.
Sullivan lost to Wai Sze Lee of Hong Kong in the 1/16 finals. The Canadian, in front, looked over her right shoulder and her opponent took advantage to shoot down the banked curve on her left to take the lead.
The 23-year-old Sullivan, a double gold medallist at the Pan American Cycling Championships, was sixth in the keirin last Friday. The keirin is an eight-lap race that sees riders jockey for position behind a motorized pace bike, which pulls away with 2.5 laps remaining to allow the final free-for-all sprint.
"I think the keirin did take the edge off me a little bit," said Sullivan, who was unhappy with he qualifying time Sunday. "But I just tried to fight through the sprints as best as I could."
Britain's Victoria Pendleton had the fastest qualifying time with an Olympic record 10.724 seconds, erasing her own mark of 10.963 in Beijing. Pendleton, who won gold earlier in the keirin and who is the defending Olympic sprint champion, joined Meares in the quarter-finals.
The women's sprint runs through Tuesday.
Britain's Jason Kenney advanced to the final four of the men's sprint along with world champion Gregory Bauge of France, Australian Shane Perkins and Njisane Nicholas Phillip of Trinidad and Tobago.